X-ray target for forming spatially divided x-rays, target module having same, and radiation treatment apparatus having same

Abstract

Provided are an X-ray target for forming spatially divided X-rays, a target module having same, and a radiation treatment apparatus having same. An X-ray target according to an embodiment of the present invention generates spatially divided X-rays through collision with an electron beam.

Description

X-ray target for forming spatially divided X-rays, target module having the same, and radiation therapy device having the same

[0001] The present invention relates to an X-ray target that generates X-rays by colliding with an electron beam and a target module having the same, and more particularly, to an X-ray target for forming spatially divided X-rays and a target module having the same.

[0002] Medical linear accelerator-based radiation therapy for cancer is a medical device that treats cancer by irradiating tumors within the patient with high-energy X-rays generated by a linear accelerator. Typically, high-power electromagnetic wave energy is used to accelerate an electron beam in a linear accelerator. The accelerated electron beam collides with an X-ray target, such as tungsten, and X-rays are generated through the bremsstrahlung effect.

[0003] Typically, radiation therapy involves irradiating patients with X-rays generated by a linear accelerator mounted on a rotating gantry. To reduce treatment time and enhance therapeutic efficacy, the X-ray dose is increased. However, high-dose X-rays administered during radiation therapy can cause radiation toxicity to normal tissues surrounding the tumor.

[0004] Research is underway to develop spatially fractionated X-ray beams to enhance therapeutic efficacy while minimizing radiation toxicity. The use of spatially fractionated X-ray beams in radiotherapy can increase peak X-ray dose while maintaining the same average X-ray dose used in cancer treatment, thereby maximizing therapeutic efficacy even with the same average dose.

[0005] To this end, a study was conducted to place a metal structure, i.e., a grid, with holes formed on the path through which X-rays generated from a linear accelerator are irradiated to a patient, thereby generating spatially divided X-rays by allowing X-rays to pass through only the areas with holes in the metal structure, and then irradiating these to a patient to increase the therapeutic effect.

[0006] However, these conventional technologies have the inconvenience of requiring an additional metal structure to be installed between the linear accelerator and the patient to generate spatially divided X-rays, and when the linear accelerator system is rotated during radiation therapy and X-rays for cancer treatment are irradiated, the problem of interference between the metal structure placed apart from the linear accelerator system and each other may occur, making the operation of the radiation therapy device complicated.

[0007] The problem to be solved by the present invention is to provide a new technology capable of generating space-segmented X-rays without complicating the structure or operation of a radiation therapy device.

[0008] According to one embodiment of the present invention, an X-ray target is provided that generates spatially separated X-rays by colliding electron beams.

[0009] In one embodiment, the X-target may include a primary target region that generates X-rays; and a secondary target region that does not generate X-rays or generates X-rays at a dose less than that generated in the primary target region.

[0010] In one embodiment, the auxiliary target area may include a hole or a groove.

[0011] In another embodiment, the auxiliary target region may comprise a material different from the material of the primary target region.

[0012] The above primary target area may include a mesh shape or multiple island shapes.

[0013] The above mesh shape or multiple island shapes may include a two-dimensional Bravis lattice structure.

[0014] The above X-ray target can generate X-rays so that a dose region higher than the average dose and a dose region lower than the average dose are formed.

[0015] The area of ​​higher dose than the average dose may include a mesh shape or multiple island shapes.

[0016] The above mesh shape or multiple island shapes may include a two-dimensional Bravis lattice structure.

[0017] Areas of dose lower than the average dose may include areas of zero dose.

[0018] An X-ray target module according to one embodiment of the present invention comprises: a flange; a target support coupled to the flange; and the above-described X-ray target held in the target support.

[0019] A radiation therapy device according to one embodiment of the present invention includes an electron beam accelerator and the X-ray target module coupled to the electron beam accelerator.

[0020] The present invention generates spatially divided X-rays using an X-ray target without adding a metal structure such as a grid. Therefore, it is possible to easily form spatially divided X-rays of various patterns without complicating the structure or operation of a radiation therapy device.

[0021] FIG. 1 is a schematic cross-sectional view of a space-segmented X-ray generating device for explaining an X-ray target module according to one embodiment of the present invention.

[0022] FIG. 2A is a schematic perspective view illustrating a target module for forming a space-segmented X-ray according to one embodiment of the present invention.

[0023] Figure 2b is a cross-sectional perspective view of Figure 2a.

[0024] FIG. 3 is a schematic perspective view illustrating an X-ray target for forming a space-segmented X-ray according to one embodiment of the present invention.

[0025] FIG. 4 is a schematic cross-sectional view illustrating an X-ray target for forming a space-segmented X-ray according to one embodiment of the present invention.

[0026] FIG. 5 is a schematic cross-sectional view illustrating an X-ray target for forming a space-segmented X-ray according to another embodiment of the present invention.

[0027] FIG. 6 is a schematic cross-sectional view illustrating an X-ray target for forming a space-segmented X-ray according to another embodiment of the present invention.

[0028] Figure 7 is a schematic perspective view illustrating a radiation therapy device according to one embodiment of the present invention.

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments introduced below are provided as examples to ensure that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below and may be embodied in other forms. Like reference numbers designate like elements throughout the specification.

[0030] FIG. 1 is a schematic cross-sectional view of a space-segmented X-ray generating device for explaining an X-ray target module according to one embodiment of the present invention.

[0031] Referring to FIG. 1, the space-segmented X-ray generating device may include an electron gun (10), an electron beam accelerator (20), an X-ray target module (30), and a collimator (40).

[0032] The electron gun (10) generates an electron beam by utilizing a high voltage difference between the cathode and the anode. The electron beam generated from the electron gun (10) is directed in a straight line by the applied electric field and is incident on the electron beam accelerator (20).

[0033] The electron beam accelerator (20) has an electron gun port (21) to which an electron gun is coupled and an output port (23) to which an X-ray target module (30) is coupled. The electron beam accelerator (20) accelerates an electron beam (EB) incident from the electron gun (10). A conventional electron beam accelerator can be used as the electron beam accelerator (20) according to the present embodiment. As an example of the electron beam accelerator, the linear accelerator introduced in the paper "Medical X-band linear accelerator for high-precision radiotherapy" by Lee et al. (Medical Physics; 2021; 00:1-16) can be cited. The contents of the paper above are incorporated herein.

[0034] An electron beam (EB) accelerated in an electron beam accelerator (20) collides with an X-ray target in an X-ray target module (30), thereby generating X-rays (Lx) from the X-ray target. The X-ray target module (30) is coupled to an output port (23) of the electron beam accelerator (20).

[0035] The collimator (40) may be, for example, a multi-leaf collimator. The collimator (40) determines the field of view (FOV) for the area of ​​interest of the subject, and collimates the X-rays generated from the X-ray target module (30) so that they are irradiated to the area of ​​interest of the subject.

[0036] The space-segmented X-ray generator can be mounted within a radiation therapy machine, which will be described later.

[0037] FIG. 2a is a schematic perspective view illustrating a target module (30) for forming a space-segmented X-ray according to one embodiment of the present invention, and FIG. 2b is a cross-sectional perspective view of FIG. 2a.

[0038] Referring to FIGS. 2a and 2b, the X-ray target module (30) includes a flange (31), a target support (33), and an X-ray target (35). The X-ray target module (30) may also include a cooling path, and may include an inlet pipe (37a) through which cooling water enters and a discharge pipe (37b) through which cooling water exits.

[0039] The flange (31) has a structure that can be coupled to the output port (23) of the electron beam accelerator (20). The flange (31) may be a circular plate having an opening formed in the center and may have a structure in which a step is formed on the inside. In addition, the flange (31) may have a plurality of bolt holes on the circumference and may be coupled to the output port (23) by bolt joint. The flange (31) may be formed of, for example, stainless steel (e.g., SUS304, etc.), but is not limited thereto.

[0040] The target support (33) is coupled to the flange (31). The target support (33) can be fitted to the flange (31) and joined to the flange by brazing.

[0041] The target support (33) supports the X-ray target (35). The target support (33) may be formed of a metal having a lower atomic weight than the X-ray target (35), such as aluminum, carbon, or copper. The target support (33) may have a groove (33g) on ​​the opposite side of the surface to which the target (35) is attached. By forming the groove (33g), it is possible to prevent X-rays generated at the target (35) from being absorbed by the target support (33), and at the same time, it is possible to block an electron beam passing through the target (35).

[0042] The target support (33) may have a cooling path inside, and the cooling water that enters through the cooling water inlet pipe (37a) flows along the path inside the target support (33) and exits through the cooling water discharge pipe (37b). The cooling water cools the heat generated in the process of generating X-rays by collision with an electron beam (EB).

[0043] An X-ray target (35) is bonded to a target support (33). The X-ray target (35) is formed of a metal having a relatively high atomic weight, such as tungsten, gold, platinum, tantalum, etc. The higher the atomic weight, the better bremsstrahlung radiation is generated. The X-ray target (35) can be bonded to the target support (33), for example, by vacuum brazing.

[0044] When a high-energy electron beam (EB) collides with a metal X-ray target (35), X-rays are generated by bremsstrahlung, and a significant amount of energy is converted into heat during the bremsstrahlung process, and some electrons pass through the X-ray target (35). Therefore, the X-ray target (35) needs to be formed of a material having a high melting point and high thermal conductivity, and a cooling device is also required to cool the generated heat. Meanwhile, electrons passing through the X-ray target (35) can be filtered by a thin film of the target support (33) disposed between the groove (33g) of the target support (33) and the X-ray target (35). The thin film of the target support (33) allows the generated X-rays to pass through.

[0045] The specific structure of the X-ray target (35) will be described in detail with reference to FIGS. 3 and 4. FIG. 3 is a schematic perspective view for explaining an X-ray target (35) for forming a space-divided X-ray according to one embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view for explaining an X-ray target (35) for forming a space-divided X-ray according to one embodiment of the present invention.

[0046] Referring to FIGS. 3 and 4, the X-ray target (35) according to the present embodiment may have an overall disk shape. Both sides of the X-ray target (35) may be flat, but are not limited thereto, and at least one side may be formed convexly. For example, the side bonded to the target support (33) may be formed convexly and may be bonded to a concave surface formed on the target support (33).

[0047] The X-ray target (35) has a main target area (35t) and an auxiliary target area (35h). In the present embodiment, the auxiliary target area (35h) may be a hole formed in the X-ray target (35). The auxiliary target area (35h) is surrounded by the main target area (35t). For example, the main target area (35t) may have a mesh shape. For example, the X-ray target (35) may be formed by forming a plurality of holes (35h) in a disk formed of a target material. The holes (35h) may be arranged at a set interval. The mesh shape may have a two-dimensional Bravis lattice structure. The two-dimensional Bravis lattice structure has five types, namely, a parallelogram system (or oblique system), a rectangular system, a rhombic system, a hexagonal system, and a square system, depending on the arrangement of the lattice points. However, the present invention is not limited thereto, and the mesh shape may be irregular.

[0048] When the electron beam (EB) collides with the X-ray target (35), X-rays (Lx) are generated in the main target area (35t). Meanwhile, the electron beam (EB) will pass through the hole (35h) and collide with the target support (33) without generating X-rays. Accordingly, the X-rays (Lx) generated from the X-ray target (35) may be mesh-shaped, space-divided X-rays. Meanwhile, the energy of the electron beam colliding with the target support (33) may generate relatively weak X-rays or may be converted into heat without generating X-rays. The target support (33) may be connected to the ground, and electrons captured by the target support (33) may escape to the ground.

[0049] In this embodiment, the auxiliary target area (35h) does not generate X-rays and thus creates a zero-dose area. On the other hand, the main target area (35t) of the X-ray target (35) creates a dose area higher than the average dose.

[0050] According to the present embodiment, space-segmented X-rays are generated by forming a hole in the X-ray target (35). In the present embodiment, since the space-segmented X-rays are generated by forming a hole in the X-ray target (35), there is no need to add a separate metal structure such as a grid as in the related art. In addition, since the X-ray target (35) is formed as a target module (30) and coupled to the electron beam accelerator (20), no interference problem occurs when the radiation therapy device is operated while rotating the gantry. Therefore, by adopting the X-ray target (35) according to the present embodiment, space-segmented X-rays can be easily generated without complicating the operation of the radiation therapy device, thereby enabling space-segmented X-ray treatment, thereby maximizing the effectiveness of cancer treatment.

[0051] FIG. 5 is a schematic cross-sectional view illustrating an X-ray target (35a) for forming a space-segmented X-ray according to another embodiment of the present invention.

[0052] Referring to FIG. 5, the X-ray target (35a) according to the present embodiment is generally similar to the X-ray target (35) described with reference to FIGS. 3 and 4, but differs in that the auxiliary target area (35g) is a groove instead of a hole. That is, the auxiliary target area (35g) does not completely penetrate the X-ray target (35a), and a target material having a relatively thin thickness exists on the bottom surface of the auxiliary target area (35g).

[0053] Accordingly, X-rays can be generated by the electron beam (EB) not only in the main target area (35t) but also in the auxiliary target area (35g). However, due to the difference in the thickness of the target material, a relatively strong first X-ray (Lx1) can be generated in the main target area (35t), and a relatively weak second X-ray (Lx2) can be generated in the auxiliary target area (35g).

[0054] In this embodiment, the groove (35g) is illustrated and described as being formed on the upper surface side of the X-ray target (35a), i.e., the side where the electron beam (EB) is incident, but is not limited thereto, and may be formed on the lower surface side of the X-ray target (35a), i.e., the side where the X-ray is emitted.

[0055] In addition, in the present embodiment, the auxiliary target area (35g) may be arranged in an island shape, similar to the auxiliary target area (35h) described with reference to FIGS. 3 and 4. Accordingly, the main target area (35t) may have a mesh shape. Alternatively, the auxiliary target area (35g) may be arranged in a mesh shape, and the main target area (35t) may be formed of a plurality of islands. In this case, the first X-ray (Lx1) generated in the main target area (35t) may have a horizontal cross-section of a plurality of island shapes. When the main target area (35t) has a mesh shape or an island shape, the mesh shape or the island shape may have a two-dimensional Bravis lattice structure. However, the present invention is not limited thereto, and the mesh shape may be irregular.

[0056] According to the present embodiment, first X-rays (Lx1) of various shapes can be generated by forming an auxiliary target area (35g) using a groove.

[0057] Meanwhile, in the present embodiment, the main target area (35t) of the X-ray target (35a) generates a dose area higher than the average dose, and the auxiliary target area (35g) generates relatively weak X-rays, thus generating a dose area lower than the average dose.

[0058] FIG. 6 is a schematic cross-sectional view illustrating an X-ray target (35b) for forming a space-segmented X-ray according to another embodiment of the present invention.

[0059] Referring to FIG. 6, the X-ray target (35b) according to the present embodiment is similar to the X-ray target (35) described with reference to FIGS. 3 and 4, but in the present embodiment, the main target area (35t) and the auxiliary target area (35m) are formed of different materials.

[0060] The auxiliary target area (35m) may be formed of a metal having a smaller atomic weight than the main target area (35t), such as copper, and the main target area (35t) may be formed of an X-ray target material, such as tungsten, gold, platinum, tantalum, etc.

[0061] The auxiliary target area (35 m) may have a mesh shape with multiple holes, and the main target area (35 t) may fill the holes of the auxiliary target area (35 m).

[0062] According to the present embodiment, X-rays are mainly generated in the main target area (35t) by collision of the electron beam (EB). Since the main target area (35t) is composed of a plurality of islands, the horizontal cross-section of the X-rays generated in the main target area (35t) can have a plurality of island shapes. Relatively weak X-rays can also be generated in the auxiliary target area (35m).

[0063] In this embodiment, the auxiliary target area (35m) is described as having a mesh shape, but the present invention is not necessarily limited thereto. For example, the main target area (35t) may have a mesh shape, and the auxiliary target area (35m) may be composed of multiple islands.

[0064] When the main target area (35t) has a mesh shape or an island shape, the mesh shape or the island shape may have a two-dimensional Bravis lattice structure. However, the present invention is not limited thereto, and the mesh shape may be irregular.

[0065] In this embodiment, the main target area (35t) of the X-ray target (35b) generates a dose area higher than the average dose, and the auxiliary target area (35m) generates no X-rays or generates relatively weak X-rays, and thus generates a dose area lower than the average dose.

[0066] Figure 7 is a schematic perspective view illustrating a radiation therapy device according to one embodiment of the present invention.

[0067] Referring to FIG. 7, the radiation treatment device according to the present embodiment may include a gantry (121), a collimator (123), and a patient placement table (125) on which a patient (129) is placed.

[0068] The space-segmented X-ray generator described with reference to FIG. 1 can be placed within a rotatable gantry (121). The gantry (121) can rotate around a region of interest of a patient.

[0069] The electron beam accelerator (20) can be arranged horizontally or vertically within the gantry (121). When the electron beam accelerator (20) is arranged horizontally, the electron beam accelerated in the horizontal direction can be converted into a vertical direction using a bending magnet or the like, and thus, the X-rays (Lx) generated in the X-ray target module (35) can be irradiated in the vertical direction. When the electron beam accelerator (20) is arranged vertically, the electron beam collides with the X-ray target without a device for converting the direction of the electron beam, and thus, the X-rays (Lx) generated in the X-ray target module (35) can be irradiated in the vertical direction. In particular, the electron beam accelerator (20) according to the present embodiment has a relatively small size and can be arranged vertically within the gantry (121).

[0070] The patient placement table (125) can move the patient (129) in the horizontal and vertical directions so that the area of ​​interest of the patient (129) requiring radiation therapy is placed in the X-ray irradiation area.

[0071] The collimator (123) is located away from the space-splitting X-ray generator and collimates the generated X-rays so that they are irradiated to the area of ​​interest of the patient (129).

[0072] Although an example of a radiation therapy device has been illustrated and described, the present invention is not limited to a specific structure of a radiation therapy device. Since all radiation therapy devices that utilize X-rays include an X-ray target, the X-ray targets (35, 35a, 35b) according to the present embodiments can be applied to conventional radiation therapy devices.

[0073] Although various embodiments of the present invention have been described above, the present invention is not limited to the various embodiments and features described above, and various modifications and changes are possible within a scope that does not depart from the technical idea according to the claims of the present invention.

[0074] (Explanation of symbols)

[0075] 10: electron gun, 20: electron beam accelerator, 21: electron gun port, 23: output port, 30: X-ray target module, 35, 35a, 35b: X-ray target, 35t: main target area, 35h, 35g, 35m: auxiliary target area, 40, 100: radiotherapy unit, 121: gantry, 123: collimator, 125: patient positioning table, 129: patient, Lx: X-ray, Lx1: first X-ray, Lx2: second X-ray

Claims

1. An X-ray target that generates spatially separated X-rays by colliding electron beams.

2. In claim 1, The main target area that generates X-rays; and An X-ray target comprising an auxiliary target region that does not generate X-rays or generates X-rays at a dose less than that generated in the primary target region.

3. In claim 2, The above auxiliary target area is an X-ray target including a hole or groove.

4. In claim 2, The above auxiliary target area is an X-ray target containing a material different from the material of the above main target area.

5. In claim 2, The above main target area is an X-ray target including a mesh shape or a plurality of island shapes.

6. In claim 5, The above mesh shape or multiple island shapes are X-ray targets including a two-dimensional Bravis lattice structure.

7. In claim 1, An X-ray target that generates X-rays so as to form regions of higher than average dose and regions of lower than average dose.

8. In claim 7, An X-ray target having a higher than average dose region comprising a mesh shape or multiple island shapes.

9. In claim 8, The above mesh shape or multiple island shapes are X-ray targets including a two-dimensional Bravis lattice structure.

10. In claim 7, X-ray target containing a zero-dose region with a dose area lower than the average dose.

11. Flange; a target support coupled to the above flange; and An X-ray target module comprising an X-ray target according to any one of claims 1 to 10 held on the target support.

12. Electron beam accelerator; and A radiation therapy device comprising an X-ray target module of claim 11 coupled to the electron beam accelerator.

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