A medical particle accelerator scanning continuous irradiation beam delivery system

Abstract

The application provides a medical particle accelerator scanning type continuous irradiation beam distribution system, which comprises a mounting frame and a double scanning magnet, a scattering device, an energy continuous modulator and a switchable swingable collimator device arranged in sequence from far to near along a straight line from a point light source to an isocenter, wherein the double scanning magnet is responsible for deflecting and scanning a speed, the scattering device is responsible for changing a cylindrical scanning speed into a conical beam with a certain divergence angle, the switchable swingable collimator device is responsible for restricting the conical beam into a trapezoidal beam, and the energy continuous modulator is responsible for longitudinally pulling a Bragg peak to perform continuous irradiation of each irradiation unit.

Description

TECHNICAL FIELD

[0001] The present invention relates to a kind of medical particle accelerator scanning type continuous irradiation beam distribution system. BACKGROUND

[0002] The conventional medical particle accelerator scanning type beam distribution system generally uses the irradiation method of layer by layer scanning, adjusts the energy of layer by layer irradiation with a binary energy regulator, and adjusts the layer thickness of each layer irradiation with a rubbing plate modulator. This irradiation method is suitable for use on the synchrotron accelerator with discontinuous beam, but for the cyclotron, it fails to fully utilize the characteristics of continuous beam. SUMMARY

[0003] The present invention provides a kind of medical particle accelerator scanning type continuous irradiation beam distribution system to match the characteristics of continuous beam of cyclotron.

[0004] The technical scheme for realizing the technical purpose of the present invention is as follows: a kind of medical particle accelerator scanning type continuous irradiation beam distribution system, comprising a mounting frame, a point light source is arranged on the top of the mounting frame, the point light source vertically reaches the bottom of the mounting frame to form an isocenter; a bidirectional scanning magnet, a scattering device, an energy continuous modulator and a collimator device are arranged in the mounting frame and along the straight line from the point light source to the isocenter from far to near; the bidirectional scanning magnet deflects and scans the beam of the medical particle accelerator, the scattering device changes the deflected and scanned beam output by the bidirectional scanning magnet into a conical beam with a certain divergence angle; the energy continuous modulator longitudinally pulls the Bragg peak to perform continuous irradiation of each irradiation unit; and the collimator device restricts the conical beam into a trapezoidal beam.

[0005] Further, in the above-mentioned medical particle accelerator scanning type continuous irradiation beam distribution system, the mounting frame comprises a magnet mounting seat, two trapezoidal vertical plates, two rectangular inclined plates and a rectangular bottom plate, forming a hexahedron; the two mutually perpendicular sections of the hexahedron are trapezoidal and rectangular respectively, with the upper section being larger and the lower section being smaller.

[0006] Further, in the above-mentioned medical particle accelerator scanning type continuous irradiation beam distribution system, the bidirectional scanning magnet is arranged on the upper part of the mounting frame and comprises a scanning magnet Y and a scanning magnet X arranged horizontally above and below the mounting seat, respectively; the scanning directions of the scanning magnet Y and the scanning magnet X are perpendicular to each other.

[0007] The two magnetic pole opposite surfaces of the scanning magnet Y are mirror-imaged, the lower ends of the two excitation coils are embedded into the counterbores on the upper surface of the mounting base, and the lower surface of the magnetic yoke is connected with the upper surface of the mounting base.

[0008] From top to bottom, the geometric centers of the scanning magnet Y and the scanning magnet X coincide; and the point light source is arranged on the upper end of the two magnetic poles of the scanning magnet Y and is symmetric to the center.

[0009] Further, in the medical particle accelerator scanning continuous irradiation beam distribution system, the scattering device is arranged below the scanning magnet, and comprises a rectangular scattering sheet, a mounting plate with a rectangular counterbore and a rectangular through hole on a long side parallel to the X-axis surface, and a rectangular compression ring; the rectangular scattering sheet is embedded into the counterbores of the mounting plate and is compressed by the rectangular compression ring; the surface of the rectangular scattering sheet is horizontal; the geometric center of the rectangular scattering sheet and the rectangular through hole of the mounting plate coincides with the line connecting the point light source and the isocenter; and the rectangular through hole coincides with the maximum field in the horizontal plane under the irradiation of the point light source.

[0010] Further, in the medical particle accelerator scanning continuous irradiation beam distribution system, the energy continuous modulator is arranged below the scattering device, and comprises a group of n wedge-shaped absorbers A arranged vertically and a wedge-shaped absorber B (4-2); the wedge-shaped absorber B and the wedge-shaped absorber A are perpendicular to each other; and the wedge-shaped absorber A and the wedge-shaped absorber A are provided with swing mechanisms for swinging in the transverse direction.

[0011] Further, in the medical particle accelerator scanning continuous irradiation beam distribution system, the collimator device comprises a collimator with two parallel vertical trapezoidal holes; the collimator is arranged in a rectangular frame A and can swing left and right; the rectangular frame A is arranged on two arc-shaped guide rails A, and the center of the arc-shaped guide rails A is on the straight line connecting the point light source and the isocenter.

[0012] In the present application, the scattering device is responsible for changing the cylindrical scanning beam into a conical beam with a certain divergence angle; the switchable and swingable collimator device is responsible for restricting the conical beam into a trapezoidal beam; and the energy continuous modulator is responsible for longitudinally pulling the Bragg peak to perform continuous irradiation of each irradiation unit; the continuous irradiation of multiple irradiation units is completed, and the irradiation of a tumor at an angle is completed.

[0013] The present application will be described in more detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 , the structure and installation of the scattering device;

[0015] Figure 2 , the structure and installation of the energy continuous modulator;

[0016] Figure 3 , the structure and installation of the energy continuous modulator;

[0017] Figure 4 , the structure and installation of the energy continuous modulator;

[0018] Figure 5-1 , the structure and installation of the energy continuous modulator;

[0019] Figure 5-2 , the structure and installation of the energy continuous modulator;

[0020] Figure 5-3 , the structure and installation of the energy continuous modulator;

[0021] Figure 5-4 , the structure and installation of the energy continuous modulator;

[0022] Figure 5-5 , the structure and installation of the energy continuous modulator;

[0023] Figure 6-1 , the structure and installation of the energy continuous modulator;

[0024] Figure 6-2 , the structure and installation of the energy continuous modulator;

[0025] Figure 6-3 , the structure and installation of the energy continuous modulator;

[0026] Figure 6-4 , the structure and installation of the energy continuous modulator;

[0027] Figure 7-1 , the structure and installation of the energy continuous modulator;

[0028] Figure 7-2 , the structure and installation of the energy continuous modulator;

[0029] Figure 7-3 , the structure and installation of the energy continuous modulator;

[0030] Figure 7-4 , the structure and installation of the energy continuous modulator;

[0031] Figure 7-5, the fifth block diagram of the working principle of the distribution system.

[0032] The symbols in the figure:

[0033] 1, a mounting frame

[0034] 1-1, a magnet mounting seat

[0035] 1-2, two trapezoidal vertical plates

[0036] 1-3, two rectangular inclined plates

[0037] 1-4, a rectangular bottom plate

[0038] 2, a bidirectional scanning magnet

[0039] 2-1, a Y-direction scanning magnet Y

[0040] 2-1-1, two magnetic poles

[0041] 2-1-2, two excitation coils

[0042] 2-1-3, a magnetic yoke

[0043] 2-2, an X-direction scanning magnet X

[0044] 2-2-1, two magnetic poles

[0045] 2-2-2, two excitation coils

[0046] 2-2-3, a magnetic yoke

[0047] 3, a scattering device

[0048] 3-1, a rectangular diffuser

[0049] 3-2, a mounting plate with a rectangular counterbore and a rectangular through hole machined on the surface parallel to the X-axis

[0050] 4, an energy continuous modulator

[0051] 4-1, a set of n wedge-shaped absorbers A arranged vertically along the Z-axis

[0052] 4-1-1, an X-direction linear motion mechanism XA

[0053] 4-1-1-1, the guide rail seat of the X-direction linear motion mechanism XA

[0054] 4-1-2, an X-direction linear drive mechanism XA

[0055] 4-2, a wedge-shaped absorber B

[0056] 4-2-1, a base with one long side parallel to the X-axis

[0057] 5, a switchable swingable collimator device

[0058] 5-1, a collimator with two parallel trapezoidal holes in the Z-axis direction

[0059] 5-2, a linear movement in the X-axis direction XB

[0060] 5-3, a linear drive in the X-axis direction XB

[0061] 5-4, a rectangular frame with an open top A

[0062] 5-5, an arcuate movement mechanism A

[0063] 5-5-1, two sets of two sliders A each

[0064] 5-5-2, two arcuate guide rails A

[0065] 5-6, a rectangular frame with an open top and bottom B

[0066] 5-7, a linear drive mechanism in the X-direction XC

[0067] 5-7-1, a lever A

[0068] 5-7-2, a bearing A

[0069] 5-8, an arcuate movement mechanism B

[0070] 5-8-1, two sets of two sliders B each

[0071] 5-8-2, two arcuate guide rails B

[0072] 5-8-3, two guide rail seats

[0073] 5-9, a linear drive mechanism in the Y-direction Y

[0074] 5-9-1, a lever B

[0075] 5-9-2, a bearing B

[0076] 101, a point source

[0077] 102, an isocenter

[0078] 103, a delivery system maximum field size

[0079] 104, a beam

[0080] 104-1, a cylindrical beam

[0081] 104-2, a conical beam

[0082] 104-3, trapezoidal beam

[0083] 6, tumor

[0084] 6-1, projection of tumor

[0085] 6-2, layout of small rectangular field for treatment planning

[0086] 6-3, volume swept by Bragg peak DETAILED DESCRIPTION

[0087] Embodiment 1, this embodiment is a medical particle accelerator scanning type continuous irradiation beam distribution system, comprising a mounting frame 1, as shown in Figure 1 : a point light source 101 is arranged on the top of the mounting frame 1, the point light source 101 vertically reaches the bottom of the mounting frame 1 to form an isocenter 102; a two-way scanning magnet 2, a scattering device 3, an energy continuous modulator 4 and a collimator device 5 are arranged in the mounting frame 1 and along the straight line from the point light source 101 to the isocenter 102 from far to near; the two-way scanning magnet 2 deflects and scans the beam of the medical particle accelerator, the scattering device 3 changes the deflected and scanned beam output by the two-way scanning magnet 2 into a conical beam with a certain divergence angle; the energy continuous modulator 4 longitudinally pulls the Bragg peak to continuously irradiate each irradiation unit; and the collimator device 5 restricts the conical beam into a trapezoidal beam.

[0088] In this embodiment, the medical particle accelerator scanning type continuous irradiation beam distribution system comprises a mounting frame 1 and a two-way scanning magnet 2, a scattering device 3, an energy continuous modulator 4 and a switchable and swingable collimator device 5 arranged in the mounting frame 1 and along the straight line from the point light source 101 to the isocenter 102 from far to near.

[0089] In this embodiment, the mounting frame 1, as shown in Figure 2 , comprises a magnet mounting seat 1-1, two trapezoidal vertical plates 1-2, two rectangular inclined plates 1-3 and a rectangular bottom plate 1-4, which are actually six plates and can enclose a hexahedron, as shown in Figure 2As shown, the upper base of the hexahedron is larger than the lower base. For convenience of description, the mounting frame 1 of the hexahedron is arranged in an XYZ coordinate system, wherein the XY plane is a horizontal plane, the Z axis is a vertical plane, and the X axis is a lateral direction of the display surface, and the Y axis is a longitudinal direction perpendicular to the display surface. Hereinafter, the point light source 101 is above in the vertical direction, i.e., the Z axis direction, and the straight rays emitted downward reach the isocenter 102, and this section can also be a section on the Z axis. Specifically, the mounting seat 1-1 is rectangular, and in an XYZ rectangular coordinate system with the isocenter 102 as the origin, the surface thereof is parallel to and above the XY plane, the long side thereof is parallel to the X axis, and the upper and lower surfaces thereof are processed with rectangular recesses, and the rectangular recesses are processed with rectangular through holes, and the geometric centers of the rectangular recesses and the rectangular through holes coincide with the Z axis in the Z axis direction; as shown in Figure 5-4 As shown, the projection of the rectangular through hole on the mounting seat 1-1 on the XY plane under the irradiation of the light source 101 coincides with the maximum field of the beam delivery system 103; the upper end surfaces of the wide sides of the two trapezoidal vertical plates 1-2 are connected to the lower surface of the mounting seat 1-1, the two inner side surfaces thereof are parallel to the YZ plane and are in mirror symmetry with respect to the YZ plane; the surfaces of the two rectangular inclined plates 1-3 are parallel to the X axis and are connected to the two inclined end surfaces of the two trapezoidal vertical plates 1-2, respectively; the surface of the rectangular bottom plate 1-4 is parallel to the horizontal plane (XY plane), the upper surface thereof is connected to the bottom surfaces of the two trapezoidal vertical plates 1-2 and the two inclined plates 1-3, and the surface thereof is processed with a trapezoidal through hole, and the geometric center of the trapezoidal through hole coincides with the Z axis in the Z axis direction, as shown in Figure 5-4 As shown, the four inclined inner walls of the trapezoidal through hole are parallel to the X axis and the Y axis, respectively, and are parallel to the rays emitted by the point light source 1-1, and the projection thereof on the XY plane coincides with the maximum field of the beam delivery system 103.

[0090] As shown in Figure 1 and Figure 3As shown, the bidirectional scanning magnet 2 includes a Y (left-right) direction scanning magnet Y2-1 and an X direction scanning magnet X2-2, which are separately arranged above and below the mounting base 1-1. The scanning magnet Y2-1 has two magnetic poles 2-1-1 whose opposite surfaces are parallel to the YZ plane and are in mirror-symmetrical positions relative to the YZ plane, two excitation coils 2-1-2 whose lower ends are deeply embedded into the counterbores on the upper surface of the mounting base 1-1, and a magnetic yoke 2-1-3 whose lower surface is connected to the upper surface of the mounting base 1-1. The scanning magnet X2-2 has two magnetic poles 2-2-1 whose opposite surfaces are parallel to the YZ plane and are in mirror-symmetrical positions relative to the YZ plane, two excitation coils 2-2-2 whose upper ends are deeply embedded into the counterbores on the lower surface of the mounting base 1-1, and a magnetic yoke 2-2-3 whose upper surface is connected to the lower surface of the mounting base 1-1. As viewed from the Z axis direction, i.e., from above, the geometric centers of the scanning magnet Y2-1 and the scanning magnet X2-2 coincide with the Z axis. The intersection of the plane on which the upper surfaces of the two magnetic poles 2-1-1 of the scanning magnet Y2-1 are located and the Z axis is defined as the position of the point light source 101.

[0091] In the figure, the mounting base 1-1 is cut open to show the magnetic poles 2-2-1 and the coils 2-2-2 of the scanning magnet X2-2, and the magnetic poles 2-1-1 and the magnetic poles 2-2-1 are shown with a distance between them.

[0092] As shown in Figure 1 and Figure 4 , the scattering device 3 is arranged below the bidirectional scanning magnet 2 and includes a rectangular scattering sheet 3-1, a mounting plate 3-2 having rectangular counterbores and rectangular through holes formed on the surface parallel to the X axis, and a rectangular compression ring 3-3. The rectangular scattering sheet 3-1 is embedded into the counterbores of the mounting plate 3-2 and is compressed by the rectangular compression ring 3-3. The surface of the rectangular scattering sheet 3-1 is parallel to the XY plane, and the geometric centers of the rectangular scattering sheet 3-1 and the rectangular through holes of the mounting plate 3-2 coincide with the Z axis as viewed from the Z axis direction, as shown in Figure 5-4 , the projection of the rectangular through holes on the XY plane under the irradiation of the point light source 101 coincides with the maximum field 103. The two ends of the elongated mounting plate 3-2 are connected to the inner surfaces of the two trapezoidal vertical plates 1-2.

[0093] In the figure, the rectangular scattering sheet 3-1 and the rectangular compression ring 3-3 are respectively moved upward by a distance, and the left trapezoidal vertical plate 1-2 is also moved away by a distance.

[0094] As shown in Figure 1 and Figure 5-1As shown in the figure, the energy continuous modulator 4 is placed below the scattering device 3, including a set of n movable wedge-shaped absorbers A4-1 and a fixed wedge-shaped absorber B4-2 arranged in the Z-axis direction. The lower surface of the n wedge-shaped absorbers A4-1 is a plane parallel to the XY plane, and the upper surface is a slope connected to a plane parallel to the XY plane, and the two side surfaces are parallel to the X-axis. The wedge-shaped absorber B4-2 is below the n wedge-shaped absorbers A4-1, and the lower surface is a plane parallel to the XY plane, and the upper surface is a slope, and the two side surfaces are parallel to the X-axis.

[0095] As shown in the figure, Figure 5-2 The n wedge-shaped absorbers A4-1 are respectively connected to an X-direction linear motion mechanism XA4-1-1 and an X-direction linear drive mechanism XA4-1-2, and the n X-direction linear motion mechanisms XA4-1-1 and the n X-direction linear drive mechanisms XA4-1-2 are respectively connected to the inner side surfaces of the two trapezoidal vertical plates 1-2.

[0096] In order to see the internal structure of the X-direction linear motion mechanism XA4-1-1-1, the guide rail seat 4-1-1-1 of the uppermost linear motion mechanism XA4-1-1 is moved by a distance, and the linear motion mechanism XA4-1-1 is connected to the inner side surfaces of the two trapezoidal vertical plates 1-2 through the guide rail seat 4-1-1-1.

[0097] As shown in the figure, Figure 5-3 The wedge-shaped absorber B4-2 is below the n wedge-shaped absorbers A4-1, and the lower surface is connected to the upper surface of the base 4-2-1 with a long side parallel to the X-axis, and the two ends of the long base 4-2-1 are connected to the inner side surfaces of the two trapezoidal vertical plates 1-2.

[0098] As shown in the figure, Figure 5-4 The surfaces of the base 4-2-1 and the guide rail seat 4-1-1-1 of the n X-direction linear motion mechanisms XA1-1-1 are all provided with a rectangular hole, and under the irradiation of the point light source 101, their projections on the XY plane coincide with the maximum field 103.

[0099] As shown in the figure, Figure 5-1 The n wedge-shaped absorbers A4-1 are driven by the X-direction (lateral) linear drive mechanism XA of the n wedge-shaped absorbers A4-1, and the linear motion mechanism XA4-1-1 can be sequentially advanced from right to left in the X-direction, and combined with the wedge-shaped absorber B4-2, the continuous modulation of the energy of the rays can be realized.

[0100] As shown in the figure, Figure 5-5As shown, for the convenience of explanation, according to the functions of the n wedge-shaped absorbers A (4-1) in turn, a virtual lengthened wedge-shaped plate is re-made, and the wedge-shaped absorber B 4-2 is flipped and falls on the long inclined surface of the lengthened wedge-shaped plate, so that the n wedge-shaped absorbers 4-1 in turn are equivalent to the movement of the lengthened virtual wedge-shaped plate from right to left, and the wedge-shaped absorber B 4-2 slides relative to the inclined surface of the lengthened virtual wedge-shaped plate, the distance from the upper surface of the wedge-shaped absorber B 4-2 to the bottom surface of the virtual wedge-shaped plate is the combined thickness of the wedge-shaped absorber A 4-1 and the wedge-shaped absorber B 4-2, which is continuously variable, thereby realizing the function of the energy continuous modulator 4 to continuously modulate energy.

[0101] As shown in Figure 6-1 , the switchable swingable collimator device 5 includes a collimator 5-1 processed with two parallel vertical trapezoidal holes, the collimator 5-1 is movably connected with an X-axis linear movement XB5-2 and an X-axis linear drive XB5-3; the X-axis linear movement XB5-2 is connected with the bottom surface of an upper-opened rectangular frame A5-4; the X-axis linear drive XB5-3 is connected with the surface of the rectangular frame A5-4 and the two vertical surfaces perpendicular to the X-axis. In fact, the collimator 5-1 can move back and forth in the horizontal direction in the rectangular frame A5-4, that is, swing, and the swing is on the track of the rectangular frame A5-4, that is, the linear movement XB5-2, and the swing power is the linear drive XB5-3 installed on the rectangular frame A5-4, which is a motor, as shown in Figure 6-1 .

[0102] As shown in Figure 6-2 , the outer sides of the two vertical surfaces (horizontal sides) of the surface of the rectangular frame A5-4 perpendicular to the Y-axis are connected with an arc-shaped movement mechanism A5-5; the arc-shaped movement mechanism A5-5 includes two groups of two sliders A5-5-1 and two arc-shaped guide rails A5-5-2, wherein the two groups of two sliders A5-5-1 are respectively connected with the horizontal sides of the surface of the rectangular frame A5-4 and movably connected with the two arc-shaped guide rails A5-5-2; the two arc-shaped guide rails A5-5-2 are connected with the inner sides of the two vertical surfaces of the surface of an upper and lower opened rectangular frame B5-6 perpendicular to the Y-axis; the arc centers of the two arc-shaped guide rails A5-5-2 are on a straight line parallel to the Y-axis and coinciding with the upper surfaces of the two magnetic poles 2-2-1 in the X-direction scanning magnet X2-2 intersecting with the Z-axis; the two vertical surfaces of the surface of the rectangular frame B5-6 perpendicular to the X-axis are connected with an X-direction linear drive mechanism XC5-7; the X-direction linear drive mechanism XC5-7 is connected with a lever A5-7-1; the lever A5-7-1 is sleeved with a bearing A5-7-2; the bearing A5-7-2 is embedded in a U-shaped groove processed on the vertical surface of the surface of the rectangular frame A5-4 perpendicular to the Y-axis.

[0103] AsFigure 6-3 As shown, the outer sides of the two horizontal facades (horizontal facades) of the rectangular frame B5-6, which are perpendicular to the X-axis, are connected to the arc-shaped moving mechanism B5-8. The arc-shaped moving mechanism B5-8 includes two sets of two sliders B5-8-1 in each set, two arc-shaped guide rails B5-8-2, and two guide rail seats 5-8-3. The two sliders B5-8-1 in each set are connected to the outer sides of the two horizontal facades of the rectangular frame B5-6, which are perpendicular to the X-axis, and are movably connected to the two arc-shaped guide rails B5-8-2. The two arc-shaped guide rails B5-8-2 are respectively connected to the two guide rail seats 5-8-3. Connection; the two guide rail seats 5-8-3 are respectively connected to the inner sides of the two trapezoidal upright plates 1-2; the arc centers of the two arc-shaped guide rails B5-8-2 are on a straight line passing through the point light source 101 and parallel to the X-axis; the upper surface of one of the two guide rail seats 5-8-3 is connected to a linear drive mechanism Y5-9 in the Y direction; the linear drive mechanism Y5-9 is connected to a lever B5-9-1; a bearing B5-9-2 is sleeved on the lever 5-9-1; the bearing B5-9-2 is embedded in a U-shaped groove machined on a vertical surface of the rectangular frame B5-6 perpendicular to the X-axis.

[0104] In this embodiment, the collimator 5-1 can swing laterally in a rectangular frame A5-4, while the rectangular frame A5-4 moves in an arc along the arc-shaped moving mechanism A5-5 within the rectangular frame B5-6, and the rectangular frame B5-6 itself moves in an arc on the two arc-shaped guide rails B5-8-2 of the arc-shaped moving mechanism B5-8.

[0105] like Figure 6-4 As shown, the collimator 5-1, which has two parallel trapezoidal holes, can move along the linear movement XB5-2 in the X-axis direction under the drive of the linear drive XB5-3 in the X-axis direction. This makes the inner wall of one trapezoidal hole, whose four inner walls are parallel to the X-axis and Y-axis respectively, parallel to the ray emitted by the point light source 101. Driving the collimator 5-1 again makes the inner wall of the other trapezoidal hole parallel to the ray emitted by the point light source 101. This is the switchable function of the switchable and swingable collimator device 5.

[0106] Based on this, the rectangular frame A5-4 is driven to swing along the arc-shaped moving mechanism A5-5 by the linear drive mechanism XC5-7 in the X direction, and the rectangular frame B5-6 is driven to swing along the arc-shaped moving mechanism B5-8 by the linear drive mechanism Y5-9 in the Y direction. This allows the collimator 5-1 to swing bidirectionally in the X-axis and Y-axis directions respectively. During the process, the characteristic that the inner wall of the trapezoidal hole on the collimator 5-1 is parallel to the rays emitted by the point light source 101 remains unchanged. This is the swing function of the switchable and swingable collimator device 5.

[0107] The working principle of the medical particle accelerator scanning continuous irradiation beam delivery system in this embodiment:

[0108] likeFigure 7-1 As shown, the undeflected beam 104 from point light source 101 to isocenter 102 can be divided into three segments: 104-1 from point light source 101 to rectangular diffuser 3-1, 104-2 from rectangular diffuser 3-1 to collimator 5-1, and 104-3 from collimator 5-1 to isocenter 102. Beam 104-1 is cylindrical, beam 104-2 (scattered by the diffuser) is conical, and beam constrained by collimator 5-1 is trapezoidal 104-3. Its projection onto the XY plane (horizontal plane) is a small square. The rectangular diffuser 3-1 does not need to be very thick; it only needs to ensure that the projection of beam 104-2 scattered by it onto the XY plane covers the projection of trapezoidal beam 104-3. When the beam 104 oscillates due to the deflection of the Y-direction scanning magnet Y2-1 and the X-direction scanning magnet X2-2, the X-direction linear drive mechanism XC5-7 and the Y-direction linear drive mechanism Y5-9 drive the collimator 5-1 to oscillate, so that the projection of the conical beam 104-2 on the XY plane always covers the projection of the trapezoidal beam 104-3 on the XY plane.

[0109] Figure 7-2 The image shown is a tumor 6 reconstructed from a CT scan. Figure 7-3 The image shows the projection 6-1 of tumor 6 onto the XY plane under the illumination of point light source 101. Figure 7-4 As shown, the projection 6-1 of tumor 6 in the XY plane is divided into several small blocks by using an area of ​​the same size as the projection of trapezoidal beam 104-3 in the XY plane. These blocks include the blocks corresponding to the projections of the two trapezoidal apertures of collimator 5-1. For comparison, the left side of the figure shows the projection 6-1 of tumor 6 in the XY plane side by side. The outlines of the two figures are basically consistent, with only a very small error. Figure 7-5 The image shows the irradiation effect of a scanning continuous beam delivery system. The principle and process are as follows:

[0110] 1. The energy of the beam (04) varies, so the range of the beam entering the human body is different. The end of the range is the location of the Bragg peak, where the dose is extremely high.

[0111] 2. Use Y-direction scanning magnet Y2-1 and X-direction scanning magnet X2-2 to deflect beam 104. At the same time, use X-direction linear drive mechanism XC5-7 and Y-direction linear drive mechanism Y5-9 to deflect collimator 5-1, so that the projection of trapezoidal beam 104-3 coincides with a small block of tumor 6 on the projection 6-1 of the XY plane. At this time, beam 104 is a virtual beam that has not yet been activated.

[0112] 3. The range of the virtual velocity beam 104 is continuously modulated by the energy continuous modulator 4, so that the Bragg peak moves from below the tumor 6 to above the tumor 6 and approaches the tumor 6.

[0113] 4. When the Bragg peak reaches near the lower boundary of the tumor, the beam is activated.

[0114] 5. The energy continuous modulator 4 continues to pull the Bragg peak upward.

[0115] 6. When the Bragg peak is about to leave the upper boundary of tumor 6, shut off the beam.

[0116] 7. The switching firing speed can be controlled by the Y-direction scanning magnet Y2-1. When a large current is applied to the excitation coil 2-1-2 of the scanning magnet Y2-1, the angle at which the Y-direction scanning magnet Y2-1 deflects the firing beam 104 will increase, causing the firing beam 104 to hit the upper surface of the magnetic pole 2-2-1 of the X-direction scanning magnet X2-2, thus blocking the firing speed. When the applied current is removed, the excitation coil 2-1-2 returns to its original operating state.

[0117] The function of switching the firing rate can also be handled by a dedicated switching magnet, but that would take up vertical space.

[0118] 8. For each small tumor, repeat steps 2 to 7. Each tumor is irradiated at one angle.

[0119] like Figure 7-5 As shown in the figure, each longitudinal square cross-section represents the volume swept by the Bragg peak. For comparison, tumor 6 is shown side-by-side on the left side of the figure. To ensure high irradiation efficiency, scanning continuous beam delivery systems are suitable for smaller and more complex-shaped tumors. For larger, less complex-shaped tumors, expanding continuous beam delivery systems can be used.

Claims

1. A medical particle accelerator scanning continuous irradiation beam distribution system, comprising a mounting frame (1), a point light source (101) is arranged on the top of the mounting frame (1), the point light source (101) vertically reaches the bottom of the mounting frame (1) to form an isocenter (102); characterized in that: In the installation frame (1) and along the straight line from the point light source (101) to the isocenter (102) by far and near in turn arranged bidirectional scanning magnet (2), scattering device (3), energy continuous modulator (4) and collimator device (5); The bidirectional scanning magnet (2) deflects and scans the beam of the medical particle accelerator, the scattering device (3) changes the deflected and scanned beam output by the bidirectional scanning magnet (2) into a conical beam with a certain divergence angle; The energy continuous modulator (4) longitudinally pulls the Bragg peak to perform continuous irradiation of each irradiation unit; The collimator device (5) restricts the conical beam into a trapezoidal beam, the collimator device (5) includes a collimator (5-1) with two parallel vertical trapezoidal holes, the collimator (5-1) is movably connected with an X-axis linear movement (XB5-2) and an X-axis linear drive (XB5-3); The X-axis linear movement (XB5-2) is connected with the bottom surface of a rectangular frame A (A5-4) with an upper opening; The X-axis linear drive (XB5-3) is connected with the two vertical surfaces of the surface of the rectangular frame A (A5-4) perpendicular to the X-axis, and the outer sides of the horizontal lateral surfaces of the surface of the rectangular frame A (A5-4) perpendicular to the Y-axis are connected with an arc-shaped movement mechanism A (A5-5); The arc-shaped movement mechanism A (A5-5) includes two groups, each group including two sliders A (A5-5-1) and an arc-shaped guide rail A (A5-5-2), the two groups of sliders A (A5-5-1) are respectively connected with the two horizontal lateral surfaces of the rectangular frame A (A5-4) and movably connected with the two arc-shaped guide rails A (A5-5-2); The two arc-shaped guide rails A (A5-5-2) are connected with the inner sides of the two vertical surfaces of the surface of a rectangular frame B (B5-6) with an upper and lower opening; The outer sides of the horizontal vertical surfaces of the surface of the rectangular frame B (B5-6) perpendicular to the X-axis are connected with an arc-shaped movement mechanism B (B5-8), the arc-shaped movement mechanism B (B5-8) includes two groups, each group including two sliders B (B5-8-1), an arc-shaped guide rail B (B5-8-2) and a guide rail seat (5-8-3), the collimator (5-1) swings horizontally in a rectangular frame A (A5-4), the rectangular frame A (A5-4) moves in an arc-shaped manner along the arc-shaped movement mechanism A (A5-5) in the rectangular frame B (B5-6), and the rectangular frame B (B5-6) itself moves in an arc-shaped manner on the two arc-shaped guide rails B (B5-8-2) of the arc-shaped movement mechanism B (B5-8).

2. The medical particle accelerator scanned continuous irradiation beamlet delivery system of claim 1, wherein: The installation frame (1) includes a magnet mounting seat (1-1), two trapezoidal vertical plates (1-2), two rectangular inclined plates (1-3) and a rectangular bottom plate (1-4), which form a hexahedron; The two mutually perpendicular sections of the hexahedron are trapezoidal and rectangular, respectively, with the upper section being larger and the lower section being smaller.

3. The medical particle accelerator scanned continuous irradiation beamlet delivery system of claim 2, wherein: The bidirectional scanning magnet (2) is arranged on the upper part of the mounting frame (1), and comprises scanning magnet Y (2-1) and scanning magnet X (2-2) which are horizontally arranged above and below the mounting base (1-1), and the scanning directions of the scanning magnet Y (2-1) and the scanning magnet X (2-2) are perpendicular to each other. The two magnetic poles (2-1-1) of the scanning magnet Y (2-1) are arranged in mirror image on the opposite surfaces, the lower ends of the two excitation coils (2-1-2) are embedded into the counterbores on the upper surface of the mounting base (1-1), and the lower surface of the magnetic yoke (2-1-3) is connected with the upper surface of the mounting base (1-1); the two magnetic poles (2-2-1) of the scanning magnet X (2-2) are perpendicular to the surfaces of the two magnetic poles (2-1-1) of the scanning magnet Y (2-1), the upper ends of the two excitation coils (2-2-2) are embedded into the counterbores on the lower surface of the mounting base (1-1), and the upper surface of the magnetic yoke (2-2-3) is connected with the lower surface of the mounting base (1-1). When viewed from top to bottom, the geometric centers of the scanning magnet Y (2-1) and the scanning magnet X (2-2) coincide; and the point light source (101) is arranged on the upper end surface of the two magnetic poles (2-1-1) of the scanning magnet Y (2-1) in symmetry center.

4. The medical particle accelerator scanned continuous irradiation beamlet delivery system of claim 3, wherein: A scattering device (3) is arranged below the scanning magnet (2), and comprises a rectangular scattering sheet (3-1), a mounting plate (3-2) with a rectangular counterbore and a rectangular through hole processed on the surface parallel to the X axis, and a rectangular compression ring (3-3); the rectangular scattering sheet (3-1) is embedded into the counterbore of the mounting plate (3-2) and is pressed by the rectangular compression ring (3-3), the surface of the rectangular scattering sheet (3-1) is horizontal, and when viewed along the direction from the point light source (101) to the isocenter (102), the geometric center of the rectangular scattering sheet (3-1) and the rectangular through hole of the mounting plate (3-2) coincides with the line connecting the point light source (101) and the isocenter (102), and the rectangular through hole coincides with the maximum field (103) on the horizontal plane under the irradiation of the point light source (101); the two ends of the mounting plate (3-2) are connected with the inner side surfaces of the two trapezoidal vertical plates (1-2).

5. The medical particle accelerator scanned continuous irradiation beamlet delivery system of claim 4, wherein: An energy continuous modulator (4) is arranged below the scattering device (3), and comprises a group of n wedge-shaped absorbers A (4-1) arranged in vertical direction and a wedge-shaped absorber B (4-2); the wedge-shaped absorber B (4-2) and the wedge-shaped absorber A (4-1) are perpendicular to each other; and the wedge-shaped absorber A (4-1) and the wedge-shaped absorber A (4-1) are provided with swing mechanisms for swinging in the transverse direction.

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