WO2018014343A1

WO2018014343A1 - Motion control method and therapeutic device of multileaf collimator

Info

Publication number: WO2018014343A1
Application number: PCT/CN2016/091062
Authority: WO
Inventors: 刘海峰
Original assignee: 深圳市奥沃医学新技术发展有限公司; 西安大医数码技术有限公司
Priority date: 2016-07-22
Filing date: 2016-07-22
Publication date: 2018-01-25
Also published as: CN109661255A

Abstract

A motion control method and a therapeutic device of a multileaf collimator (10) relating to the technical field of medical equipment. The multileaf collimator (10) can adjust a conformal position with patient's breath, thus avoiding the irradiation of normal tissues. A motion control method of a multileaf collimator (10), comprising: driving blades (111) to move to form a radiation beam-passable region (20) adapted to the shape of a tumor (3); acquiring respiratory cycle signals and images of the tumor (3) during respiratory cycles; determining a motion path of the tumor (3) during the respiratory cycles according to the respiratory cycle signals and the images of the tumor (3) during the respiratory cycle; acquiring a current image of the tumor (3); determining the direction and the distance of the movement of the tumor (3) within the radiation beam cross-section according to the current image of the tumor (3); and driving a small cart (12) to move within the radiation beam cross-section according to the direction and distance of the movement of the tumor (3) within the radiation beam cross-section, so that the radiation beam-passable region (20) formed when the radiation beam passes through the blades (111) is always focused on the tumor (3).

Description

Motion control method and treatment device for multi-leaf collimator

Technical field

The invention relates to the technical field of medical instruments, in particular to a motion control method and a treatment device for a multi-leaf collimator.

Background technique

At present, radiation therapy has become one of the three major methods of cancer treatment, and more and more cancer patients receive precise radiation therapy.

As shown in FIG. 1, a schematic view of a conventional treatment device includes a radiation source 1 and a multi-leaf collimator 10 mounted at the beam exit of the radiation source 1. As shown in FIG. 2, the multi-leaf collimator 10 includes a first blade set 11a and a second blade set 11b disposed opposite each other in the first direction 101, a blade drive device, a first carriage 12a, a second carriage 12b, and a trolley drive device. . The first blade group 11a and the second blade group 11b respectively include a plurality of blades 111, and the first blade group 11a and the second blade group 11b are located on the first carriage 12a and the second carriage 12b, respectively. The blade driving device is for driving each of the first blade group 11a and the second blade group 11b to move in the first direction 101.

During the treatment, by independently moving a plurality of blades 111 arranged in parallel, the end forming beam can pass through the region 20, which in general can be adapted to the shape of the tumor through the region 20 to achieve conformality. Radiation therapy.

However, during radiotherapy, the patient's respiratory motion causes tumor displacement, which not only reduces the treatment efficiency, but also allows the patient's normal tissue to receive radiation. One existing solution is to expand the target area of the radiotherapy to fully cover the moving tumor, but this method will cause more normal tissues of the patient to receive radiation, which may easily cause secondary tumors, which is not conducive to the health of the patient. Currently, respiratory-gated radiotherapy is also used to irradiate the tumor area at the end of the patient's breath holding or inhalation. However, this method only reduces the influence of tumor movement to a certain extent, but the patient's breathing and state requirements are relatively high. High is generally difficult to achieve and increases the time of radiotherapy.

Summary of the invention

Embodiments of the present invention provide a motion control method and a treatment apparatus for a multi-leaf collimator capable of adjusting a conformal position with a patient's breathing, thereby avoiding alignment Regular tissue radiation.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

In a first aspect, an embodiment of the present invention provides a motion control method for a multi-leaf collimator, the multi-leaf collimator includes: two blade sets disposed opposite to each other, and a small car, the blade set including a plurality of blades, a blade set is disposed on the trolley; the control method includes:

Driving the blade to move to form a beam traversable region adapted to the shape of the tumor;

Obtaining a respiratory cycle signal and an image of the tumor during the respiratory cycle;

Determining a path of motion of the tumor during the respiratory cycle based on the respiratory cycle signal and an image of the tumor during the respiratory cycle;

Obtain the current image of the tumor;

Determining a direction and a distance of movement of the tumor within a cross section of the beam based on a current image of the tumor;

The carriage is moved within the cross-section of the beam of light according to the direction and distance the tumor moves within the cross-section of the beam such that the beam formed by the beam of radiation through the blade can be focused on the tumor through the region.

Optionally, the beam is periodically emitted;

The driving the carriage to move within the cross section of the beam according to the direction and distance of movement of the tumor within the cross section of the beam of beam specifically includes:

The carriage is moved during the time the beam is turned off, such that the beam formed by the beam through the blade at the beginning of the next illumination can be focused on the tumor through the region.

Optionally, the driving the moving of the trolley in the cross section of the beam according to the direction and distance that the tumor moves within the cross section of the beam beam comprises:

Determining the distance between the source of radiation, the multi-leaf collimator, and the tumor;

Determining a moving distance of the multi-leaf collimator according to the distance between the radiation source, the multi-leaf collimator, and the tumor, and the direction and distance the tumor moves within the cross-section of the beam;

The cart is driven to move the moving distance in a direction of movement of the tumor.

Optionally, the multi-leaf collimator is fixed on the treatment head, and the treatment head is circumferentially rotatable, and the motion control method further includes:

The radial and/or axial movement of the treatment head along the circumference is driven.

In another aspect, an embodiment of the present invention provides a radiotherapy apparatus, including:

a source of radiation for emitting a beam of radiation;

a multi-leaf collimator comprising: two blade sets disposed opposite each other, a carriage, a blade drive mechanism, and a trolley drive mechanism, the blade set including a plurality of blades, the blade set being disposed on the trolley; the blade drive mechanism Driving the blade to move; the trolley driving mechanism is configured to drive the trolley to move;

a respiratory monitor for acquiring a respiratory cycle signal and transmitting it to the processor;

An image collector for acquiring a tumor image and transmitting it to the processor;

a processor for determining a motion path of the tumor during a respiratory cycle according to a respiratory cycle signal acquired by the respiratory monitor and the image acquisition device acquiring a tumor image within the respiratory cycle, according to the image processor The current image of the tumor determines the direction and distance the tumor moves within the cross-section of the beam and is sent to the cart drive mechanism.

Optionally, the beam is periodically emitted;

The cart drive mechanism is further configured to drive the cart to move during a time when the beam is turned off.

Optionally, the multi-leaf collimator includes a small car, and the two blade sets are disposed on the trolley; or

The multi-leaf collimator includes two carts that are respectively disposed on the two carts.

Optionally, the trolley driving mechanism comprises: a screw rod and a driver, the trolley is connected to the screw rod; and the driver is configured to drive the trolley to move along the screw rod.

Optionally, the radiotherapy apparatus comprises a treatment head and a ring-shaped drum, the treatment head comprising the radiation source and the multi-leaf collimator;

The treatment head is disposed on the annular drum and is rotatable with the circumference of the annular drum, and the treatment head is movable in a radial direction of the annular drum.

Optionally, the radiotherapy apparatus comprises a treatment head and a guide rail, the treatment head comprising the radiation source and the multi-leaf collimator;

The treatment head is movable along the guide rail in the axial direction of the annular drum.

Embodiments of the present invention provide a motion control method and a treatment apparatus for a multi-leaf collimator, the radiation therapy apparatus comprising: two blade sets disposed opposite to each other, and a trolley, the blade set including a plurality of blades, the blade group being disposed on the trolley The drive mechanism includes: a blade drive mechanism and a carriage drive mechanism, wherein the blade drive mechanism is configured to drive the blade to move to form a compliant region through which the beam of rays can pass. a trolley driving mechanism for driving the trolley to move; a respiratory monitor for acquiring a respiratory cycle signal; an image collector for acquiring a tumor image in the respiratory cycle; and a processor for the respiratory cycle signal and the image acquired according to the respiratory monitor The collector acquires the tumor image within the respiratory cycle to determine the direction and distance the tumor moves within the cross section of the beam during the breathing cycle, and sends a drive signal to the trolley drive structure to drive the trolley to move, thereby causing the beam to pass through the blade. The beam can be focused on the tumor through the area to achieve real-time tracking of the tumor.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic view showing a treatment of a rotating treatment of a treatment device according to an embodiment of the present invention;

2 is a schematic view of a multi-leaf collimator fitting a tumor shape forming beam traversable region;

3 is a schematic diagram of a trolley according to an embodiment of the present invention;

4 is a schematic diagram of a control method of a multi-leaf collimator according to an embodiment of the present invention;

Figure 5 is a schematic diagram of a tumor image in a respiratory cycle and a respiratory cycle;

FIG. 6 is a schematic diagram of a driving car moving in a cross section of a beam according to an embodiment of the present invention; FIG.

7 is a schematic diagram showing a simplified movement of a radiation source, a multi-leaf collimator, and a tumor according to an embodiment of the present invention;

Figure 8 is a schematic illustration of the movement of the treatment head along the guide rail.

Reference mark:

1-ray source; 3-tumor; 4-treatment head; 11-blade group; 12-multi-leaf collimator; 11a-first blade group; 11b-second blade group; 12a-first car; 12b- Two trolleys; 13-spindle; 20-beam passable area; 21-rail; 22-annular drum; 111-blade; 121-upper panel; 122-lower panel.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

An embodiment of the present invention provides a radiation therapy apparatus, as shown in FIG. 1, including a radiation source 1, a multi-leaf collimator 10, a respiratory monitor, an image collector 2, and a processor; wherein the radiation source 1 is used to emit Beam of light.

The multi-leaf collimator 10, as shown in FIG. 1, includes two opposite blade groups 11 and a trolley 12, wherein the two blade groups in FIG. 1 are a first blade group 11a and a second blade group 11b, respectively. The blade group 11, including the first blade group 11a and the second blade group 11b, respectively includes a plurality of blades 111, and the first blade group 11a and the second blade group 11b are respectively disposed on the carriage 12.

It should be noted that, in the embodiment of the present invention, the first blade group 11a and the second blade group 11b are respectively disposed on the trolley 12, and the trolley may include the first trolley 12a and the second trolley 12b, and the first blade group 11a and the first The two blade groups 11b are located on the first cart 12a and the second cart 12b, respectively. Alternatively, the multi-leaf collimator includes a cart 12, and the cart 12 may be as shown in FIG. 3. The first vane set 11a and the second vane set 11b are both disposed on the cart 12, and the cart includes an upper panel 121 and a lower panel 122. The upper panel 121 and the lower panel 122 are each provided with an opening in which the conformable region formed by the blade is located, and the beam formed by the beam passing through the blade can be focused on the tumor through the region.

The multi-leaf collimator further includes a driving mechanism including: a blade driving mechanism and a trolley driving mechanism, wherein the blade driving mechanism is used to drive the blade to move; the trolley driving mechanism is used to drive Move the car. Specifically, the blade driving mechanism may be an electronic and electrical structure that can move the blade in the first direction 101, and is not specifically limited in the embodiment of the present invention.

In the embodiment of the present invention, as shown in FIG. 2, the trolley driving mechanism includes: a screw rod 13 and a driver (not shown), the trolley 12 is connected to the screw rod 13; and the driver is used to drive the trolley 12 to move along the screw rod 13. . In the embodiment of the invention, the driver can receive the driving signal of the processor and drive the trolley to move according to the driving signal of the processor. Specifically, the driver may be a driver that drives the movement of the car through an electronically controlled motor or the like, which is not specifically limited in the embodiment of the present invention. In Fig. 2, for example, the side of the trolley is located on the side of the trolley, and the screw can also be located on both sides of the trolley.

A breath monitor for acquiring a respiratory cycle signal and transmitting it to the processor. The respiratory monitor can be configured by setting a marker point on the surface of the human body, using a CCD camera or an infrared distance measuring device to form a respiratory detector, detecting a state change of the body surface in the respiratory motion, and obtaining a body surface respiratory cycle curve.

An image collector is used to acquire a tumor image and send it to the processor. By way of example, the image collector can continuously acquire a tumor image during the breathing cycle, thereby forming a schematic diagram of the respiratory cycle motion curve corresponding to the tumor image as shown in FIG. The amplitude of the corresponding moving tumor at the set point on the periodic respiratory motion curve, wherein the set point can be set by the time and the respiratory amplitude measured by the distance measuring device such as the CCD. According to such a correspondence, dynamic three-dimensional reconstruction of tumor tissue can be performed.

The processor is configured to determine a motion path of the tumor during the breathing cycle according to the respiratory cycle signal acquired by the respiratory monitor and the image acquisition device acquires the tumor image in the respiratory cycle, and send a driving signal to the driver, so that the driver drives the trolley to move.

Specifically, the processor couples the respiratory cycle signal and the tumor image in the respiratory cycle to obtain a four-dimensional image of the tumor in the free breathing cycle of the patient. Thereby obtaining the current image of the tumor, comparing the current image of the tumor with the four-dimensional image of the tumor in the free breathing cycle of the patient, thereby determining the moving method and distance of the multi-leaf collimator, thereby driving the trolley to move to form a tracking of the tumor movement, achieving precision treatment.

A radiotherapy apparatus according to an embodiment of the present invention includes: two blade groups disposed opposite to each other and a small car, the blade group includes a plurality of blades, and the blade group is disposed on the trolley; the driving mechanism includes: a blade driving mechanism and a trolley driving mechanism Wherein the blade drive mechanism is used to drive the blade movement to form a conformable region through which the beam of rays can pass. Trolley drive mechanism Used to drive the movement of the trolley; a respiratory monitor for acquiring the respiratory cycle signal; an image collector for acquiring the tumor image in the respiratory cycle; and a processor for obtaining the respiratory cycle signal acquired by the respiratory monitor and the image acquisition device The tumor image within the respiratory cycle determines the direction and distance the tumor moves within the cross-section of the beam during the breathing cycle and sends a drive signal to the cart drive structure to drive the carriage to move, thereby causing the beam to pass through the beam formed by the blade Focusing on the tumor through the region allows real-time tracking of the tumor.

It should be noted that, in the case of the tumor movement, in the embodiment provided by the embodiment of the present invention, as shown in FIG. 2, the moving carriage 12 drives the blade 111 to move, so that the blade 111 does not need to be moved again to form a shape corresponding to the tumor 3. The adapted beam can pass through the shape of the region, avoiding changes in the shape of the beam traversable region formed by the multiple movement of the blade 111.

In another embodiment provided by the embodiment of the present invention, the radiation beam is periodically emitted; and the processor is further configured to determine, according to the motion path of the tumor in the respiratory cycle, the tumor to the next irradiation at the end of the previous irradiation The direction of motion of the tumor at the beginning and the distance of motion, thereby confirming the location of the tumor at the beginning of the next irradiation. The cart drive mechanism is further configured to drive the cart to move during the time the beam is turned off, such that the beam formed by the beam passing through the blade at the beginning of the next shot can be focused on the tumor through the region.

For example, the processor is further configured to determine the moving distance of the multi-leaf collimator according to the distance between the radiation source, the multi-leaf collimator, and the tumor, and the direction and distance the tumor moves within the cross section of the beam, and send Give the car drive mechanism.

A radiation therapy apparatus according to an embodiment of the present invention, further comprising a treatment head 4 and a ring-shaped roller 22, as shown in FIG. 8, the treatment head 4 includes a radiation source 1 and a multi-leaf collimator 10, and the treatment head 4 is disposed on the annular roller 22, and rotatable around the circumference of the human body with the annular roller 22, the treatment head 4 is movable in the radial direction of the annular roller 22 (in the direction of 102 shown in Fig. 8) so as to be away from or close to the human body.

In addition, in the embodiment of the present invention, as shown in FIG. 8, the annular drum 22 is further provided with a guide rail 21, and the treatment head 4 is movable along the guide rail 21. In FIG. 8, the guide rail 21 is taken as a linear guide rail, and the guide rail may be an arc guide rail or the like to realize non-coplanar illumination.

In an embodiment of the invention, the radiation source may be any one of an X-ray source, an electron source, a nuclear source (eg, Co-60), synchrotron radiation, or a neutron source. Among them, the irradiation of the treatment head The radiation can be focused or conformal.

An embodiment of the present invention provides a motion control method for a multi-leaf collimator. Referring to FIG. 2, the multi-leaf collimator 10 includes two blade sets 11 and a trolley 12 disposed opposite to each other, wherein, in FIG. The two blade sets are a first blade set 11a and a second blade set 11b, respectively; the blade set 11 includes a first blade set 11a and a second blade set 11b, each of which includes a plurality of blades 111, respectively. The cart 12 includes a first cart 12a and a second cart 12b, and the first vane group 11a and the second vane group 11b are located on the first cart 12a and the second cart 12b, respectively.

As shown in FIG. 4, the control method includes:

Step 101, driving the blade to move to form a beam traversable region that is adapted to the shape of the tumor. Referring to Figure 2, the blade 111 is moved to form a beam traversable region 20 that is adapted to the shape of the tumor 3.

Step 102: Acquire a respiratory cycle signal and an image of the tumor during the respiratory cycle.

For example, by setting a marker point on the surface of the human body, a respiratory monitoring system is formed by using a CCD camera or an infrared distance measuring device, thereby detecting a state change of the body surface in the respiratory motion, and obtaining a respiratory cycle and an image of the tumor in the respiratory cycle, as shown in the figure. 5 is shown.

Step 103: Determine a motion path of the tumor during the respiratory cycle based on the respiratory cycle signal and the image of the tumor during the respiratory cycle. Because tumors generally follow the movement of the respiratory cycle, for example, at the end of exhalation and inhalation, the amplitude of the tumor is small; at the beginning of exhalation and inhalation, the amplitude of the tumor is larger, as shown in Figure 5. As shown, the path of motion of the tumor during the breathing cycle can be determined.

Step 104: Obtain a current image of the tumor. Illustratively, an image of a human tumor is formed by an image collector, such as a detector plate, that receives a beam of radiation that passes through a human tumor.

Step 105: Determine the direction and distance of movement of the tumor within the cross section of the beam of radiation beams based on the current image of the tumor. The current image of the tumor may be a tumor image comprising one or more frames, combined with the motion path of the tumor, to estimate the direction and distance of movement of the tumor within the cross-section of the beam of radiation beams.

Step 106: Driving the trolley to move within a cross section of the beam of the radiation beam according to a direction and a distance in which the tumor moves within a section of the beam of the radiation beam, thereby causing the beam of the beam to pass through The beam formed by the blade can be focused on the tumor through the area.

For example, referring to FIG. 1 and FIG. 2, if the tumor 3 moves to the left by a distance d3, the multi-leaf collimator moves to the left by a distance d, and is generally d≠d3.

In another implementation manner provided by the embodiment of the present invention, as shown in FIG. 6, the foregoing step 106 specifically includes:

Step 1061. Determine the distance between the radiation source, the multi-leaf collimator, and the tumor.

Referring to Figure 1, the distance between the source 1 and the multi-leaf collimator 10 is d1, and the distance between the multi-leaf collimator and the tumor 3 is d2.

Step 1062: Determine a moving distance of the multi-leaf collimator according to the distance between the radiation source, the multi-leaf collimator, and the tumor, and the direction and distance the tumor moves within the cross-section of the beam. Referring to Figures 1 and 2, the tumor 3 moves a distance d3 in the cross section of the beam. For example, referring to FIG. 1 , FIG. 2 and FIG. 7 , an approximate triangle is formed between the radiation source 1, the multi-leaf collimator 10 and the tumor 3, and the moving distance d of the multi-leaf collimator is approximately equal to (d1). ×d3)/d2, that is, the moving distance of the multi-leaf collimator can be determined by calculation.

Step 1063, driving the trolley to move the moving distance along the moving direction of the tumor.

The driving carriage moves the moving distance along the moving direction of the tumor, so that the shape of the beam traversable region which is adapted to the shape of the tumor is not required to be moved again, and the shape of the beam traversable region formed by multiple movements of the blade is prevented from changing. .

In another embodiment provided by the embodiments of the present invention, the radiation beam is periodically emitted. By way of example, referring to Figure 1, the radiation beam is periodically emitted, and the tumor moves with the breathing during the time that the beam is closed. In the embodiment provided by the embodiment of the present invention, the step 106 includes: driving the trolley to move during the time when the beam is turned off, so that the beam formed by the beam passing through the blade can be focused on the tumor through the region at the beginning of the next irradiation. on. That is, the carriage moves with the movement of the tumor during the time when the beam is closed, so that at the beginning of the next cycle, the beam formed by the beam passing through the blade can be focused on the tumor through the region.

In another embodiment provided by the embodiment of the present invention, the multi-leaf collimator is fixed on the treatment head. As shown in FIG. 1 , the treatment head is circumferentially rotatable, and the motion control method further comprises: driving the treatment head along the circumference of the axial direction. / or radial movement. As shown in Figure 8, the treatment head can also be In the radial direction of the circumference, that is, the direction of 102, or the treatment head may be moved in the axial direction of the circumference, that is, in the direction of the guide rail 21, or the treatment head may be moved in both the axial direction and the radial direction, thereby realizing the blade at different illumination positions. Beams that fit different tumor shapes can pass through the area.

For example, the circumferential direction of the treatment head can be moved along the guide rail 21 shown on the way 8. Specifically, the guide rail 21 can also be an arc-shaped guide rail, which can be the inner side of the circumference or the center of the circumference of the circumference. The embodiment of the invention is not specifically limited.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A motion control method for a multi-leaf collimator, the multi-leaf collimator comprising: two blade sets disposed opposite to each other and a trolley, the blade set including a plurality of blades, the blade group being disposed on the trolley; The method is characterized in that the control method comprises:

Driving the blade to move to form a beam traversable region adapted to the shape of the tumor;

Obtaining a respiratory cycle signal and an image of the tumor during the respiratory cycle;

Determining a path of motion of the tumor during the respiratory cycle based on the respiratory cycle signal and an image of the tumor during the respiratory cycle;

Obtain the current image of the tumor;

Determining a direction and a distance of movement of the tumor within a cross section of the beam of rays based on a current image of the tumor;

The carriage is moved within the cross-section of the beam according to the direction and distance of movement of the tumor within the cross-section of the beam such that the beam formed by the beam through the blade can be focused on the tumor through the region.
The motion control method according to claim 1, wherein the radiation beam is periodically emitted;

The driving the carriage to move within the cross section of the beam according to the direction and distance of movement of the tumor within the cross section of the beam of beam specifically includes:

The carriage is moved during the time the beam is turned off, such that the beam formed by the beam through the blade at the beginning of the next illumination can be focused on the tumor through the region.
The motion control method according to claim 1 or 2, wherein the driving the carriage in the section of the beam according to the direction and distance in which the tumor moves within the cross section of the beam beam comprises:

Determining the distance between the source of radiation, the multi-leaf collimator, and the tumor;

Determining a moving distance of the multi-leaf collimator according to the distance between the radiation source, the multi-leaf collimator, and the tumor, and the direction and distance the tumor moves within the cross-section of the beam;

The cart is driven to move the moving distance in a direction of movement of the tumor.
The motion control method according to claim 1, wherein the multi-leaf collimator is fixed to the treatment head, and the treatment head is circumferentially rotatable, and the motion control method further comprises:

The radial and/or axial movement of the treatment head along the circumference is driven.
A radiotherapy apparatus, comprising:

a source of radiation for emitting a beam of radiation;

a multi-leaf collimator comprising: two blade sets disposed opposite each other, a carriage, a blade drive mechanism, and a trolley drive mechanism, the blade set including a plurality of blades, the blade set being disposed on the trolley; the blade drive mechanism Driving the blade to move; the trolley driving mechanism is configured to drive the trolley to move;

a respiratory monitor for acquiring a respiratory cycle signal and transmitting it to the processor;

An image collector for acquiring a tumor image and transmitting it to the processor;

a processor for determining a motion path of the tumor during a respiratory cycle according to a respiratory cycle signal acquired by the respiratory monitor and the image acquisition device acquiring a tumor image within the respiratory cycle, according to the image processor The current image of the tumor determines the direction and distance the tumor moves within the cross-section of the beam and is sent to the cart drive mechanism.
The radiation therapy apparatus according to claim 5, wherein said radiation beam is periodically emitted;

The cart drive mechanism is further configured to drive the cart to move during a time when the beam is turned off.
The radiation therapy apparatus according to claim 5, wherein said multi-leaf collimator comprises a trolley, and said two blade sets are each disposed on said carriage; or

The multi-leaf collimator includes two carts that are respectively disposed on the two carts.
The radiation therapy apparatus according to claim 5, wherein said carriage driving mechanism comprises: a lead screw and a driver, said trolley being coupled to said screw; said driver for driving said carriage along said The screw moves.
The radiation therapy apparatus according to claim 5, wherein said radiation therapy apparatus comprises a treatment head and an annular roller, said treatment head comprising said radiation source and said multi-leaf collimator;

The treatment head is disposed on the annular drum and is rotatable with the circumference of the annular drum, and the treatment head is movable in a radial direction of the annular drum.
The radiation therapy apparatus according to claim 5, wherein said radiation therapy apparatus comprises a treatment head and a guide rail, said treatment head comprising said radiation source and said multi-leaf collimator;

The treatment head is movable along the guide rail in the axial direction of the annular drum.