A correction system for the settlement of a treatment bed in a spiral tomotherapy system

Abstract

The present invention proposes a correction system for the settlement of a treatment bed in a spiral tomography radiotherapy system, including an angle error sensing system, an angle error correction system and a central control system. The angle error sensing system is an angle monitor, which is installed on the head side of a position fixing frame; the angle error correction system is composed of a correction frame, a transverse correction mechanism and a longitudinal correction mechanism. The correction frame is installed on the treatment bed surface, and the transverse and longitudinal correction mechanisms are both arranged on the top surface of the correction frame; the central control system is composed of a host, a display and a control console. The host is connected to the angle monitor, receives and processes data and transmits it to the display for real-time display. The control console is connected to the host, transmits the correction command to the transverse correction mechanism and the longitudinal correction mechanism, and controls the motion correction. The present invention corrects the tilt angle α caused by settlement and the PITCH and YAW angle errors after image registration, so as to achieve the purpose of precise radiotherapy.

Description

Technical Field

[0001] The invention belongs to the technical field of radiotherapy equipment, and in particular relates to a correction system for the settlement of a treatment bed in a spiral tomographic radiotherapy system. Background Art

[0002] The spiral tomographic radiotherapy system is a radiotherapy device that combines spiral CT (Computed Tomography) and a linear accelerator. One of its notable features is that before radiotherapy, the patient is positioned with reference to the virtual isocenter of the red movable laser outside the gantry hole; during radiotherapy, radiotherapy is performed at the machine isocenter inside the gantry hole. The two centers are 700 mm apart. When the treatment bed moves from the virtual isocenter to the machine isocenter, the treatment bed sinks because the load of the treatment bed or the bed surface exceeds the bed support. The sinking causes the bed surface to tilt at an angle of α, resulting in a position error of tumor radiotherapy. The treatment target area does not accurately reach the machine isocenter position, which affects the repeatability of the target area, resulting in uneven distribution of the prescribed dose in the target area and the biological effect of the absorbed dose on tumor cells, ultimately reducing the tumor control rate and increasing the toxicity of normal tissues.

[0003] The position error caused by the settlement of the treatment bed not only affects the dose distribution of the prescribed dose in the target area, reduces the tumor control rate, but also causes irreversible damage to normal tissues and organs. The trend of spiral tomography radiotherapy system being used in clinical radiotherapy is increasing, and the problem of settlement of the treatment bed still exists. At present, the solution to the settlement problem of the treatment bed mainly relies on image-guided radiotherapy technology. The implementation of this technology faces three main problems: First, MVCT (Megavoltage Computed Tomography) images must be scanned during each radiotherapy, and the scanning radiation dose causes irreversible damage to the patient. The cumulative radiation dose of the entire course of treatment cannot be ignored. Second, without the premise of a six-dimensional treatment bed, even if image-guided radiotherapy technology is used, the PITCH (pitch angle) and YAW (yaw angle) angle errors cannot be corrected. In order to solve the problem of increased position error caused by the settlement of the treatment bed, affecting the accuracy of radiotherapy, the tumor target area is placed at the same horizontal position at the virtual isocenter and the mechanical isocenter, improving the repeatability of the target area and the accuracy of radiotherapy; in order to correct the PITCH and YAW angle errors after image registration. Therefore, it is necessary to invent a correction system to solve the settlement problem of the treatment bed. If the accuracy of the correction system meets clinical requirements, the frequency of MVCT scanning can be reduced and the scanning radiation dose can be reduced. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a correction system for the settlement of the treatment bed of a spiral tomographic radiotherapy system in response to the above-mentioned problems. By adjusting the angle of the body position fixation frame, the inclination angle α caused by the settlement and the PITCH and YAW angle errors after image registration are corrected to achieve the purpose of precise radiotherapy.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a correction system for the settlement of a treatment bed of a spiral tomographic radiotherapy system, characterized in that it includes an angle error sensing system, an angle error correction system and a central control system, wherein the angle error sensing system is an angle monitor, and the angle monitor is installed on the head side of a position fixing frame; the angle error correction system consists of a correction frame, a transverse correction mechanism and a longitudinal correction mechanism, the correction frame is installed on the treatment bed surface, and the transverse and longitudinal correction mechanisms are both arranged on the top surface of the correction frame; the central control system consists of a host, a display and a control console, the host is connected to the angle monitor, receives and processes data and transmits it to the display for real-time display, and the control console is connected to the host, transmits correction commands to the transverse correction mechanism and the longitudinal correction mechanism, and controls motion correction.

[0006] According to the above scheme, the correction frame includes a fixed frame and a suspension frame. The fixed frame is composed of left and right bases, left and right support plates and a top plate to form a door-type support frame. The suspension frame is composed of a suspension rod and a suspension frame. The suspension frame is a U-shaped frame. The bottom end of the suspension rod is fixed to the top center of the suspension frame, and the top end is connected to the longitudinal correction mechanism. The two sides of the suspension frame are connected to the two sides of the body position fixing frame on the treatment bed.

[0007] According to the above scheme, the transverse correction mechanism includes a transverse rail, a transverse slider, a transverse encoder and a transverse motor. The transverse rail is laid on the top surface of the top plate, the transverse slider is configured with the transverse rail, and slides horizontally along the transverse rail. The transverse encoder and the transverse motor are installed on the top plate and are connected through a data line. The transverse encoder is connected to the host through an optical fiber, and the transverse motor is connected to the transverse slider through a turbine worm mechanism; the longitudinal correction mechanism includes a longitudinal rail, a longitudinal slider, a longitudinal encoder and a longitudinal motor. The longitudinal rail is laid on the inner wall of the central through hole of the transverse slider, the longitudinal slider is configured with the longitudinal rail, and slides vertically along the longitudinal rail. The longitudinal encoder and the longitudinal motor are installed on the top plate and are connected through a data line. The longitudinal encoder is connected to the host through an optical fiber, and the longitudinal motor is connected to the longitudinal slider through a turbine worm mechanism. The top of the suspension rod is connected to the bottom surface of the longitudinal slider.

[0008] According to the above solution, the angle monitor is a digital tilt angle measuring instrument or a gyroscope.

[0009] According to the above solution, the correction frame is made of high molecular carbon fiber composite material.

[0010] According to the above scheme, the control console is composed of a data keyboard, a motion button and an emergency switch.

[0011] According to the above solution, the top plate is a hollow shell structure, and the transverse encoder, transverse motor, longitudinal encoder and longitudinal motor are all arranged in the internal cavity of the top plate.

[0012] The beneficial effects of the present invention are as follows: a correction system for the settlement of a treatment bed in a spiral tomographic radiotherapy system is provided, which monitors the angle value of the treatment bed in real time, adjusts the angle of the body position fixing frame through the lateral and longitudinal correction mechanisms, corrects the tilt angle α caused by the settlement and the PITCH and YAW angle errors after image registration, allows the tumor target area to be at the same horizontal position at the virtual isocenter and the machine isocenter, and improves the target area repeatability and the accuracy of the radiotherapy position. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0014] Figure 2 The figure is a schematic diagram of the correction position according to an embodiment of the present invention.

[0015] Figure 3 Schematic diagram of a coordinate system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0017] like Figure 1 As shown, the present invention provides a correction system for the settlement of a treatment bed in a spiral tomographic radiotherapy system, comprising an angle error sensing system, an angle error correction system and a central control system. The angle error sensing system is an angle monitor 11, which is mounted on the head side of a position fixing frame 7; the angle error correction system consists of a correction frame, a transverse correction mechanism and a longitudinal correction mechanism, the correction frame is mounted on the treatment bed 1, and the transverse and longitudinal correction mechanisms are both arranged on the top surface of the correction frame; the central control system consists of a host 2, a display 3 and a control console 4, the host is connected to the angle monitor, receives and processes data and transmits it to the display for real-time display, the control console is connected to the host, transmits correction commands to the transverse correction mechanism and the longitudinal correction mechanism, and controls motion correction.

[0018] The console consists of a data keyboard, motion buttons and emergency switches. The correction data input from the data keyboard is displayed on the display, and the error correction is achieved through the motion buttons. When an accident occurs, the emergency button is pressed and the correction system stops running.

[0019] The correction frame includes a fixed frame 5 and a suspension frame 6. The fixed frame is composed of a left and right base, a left and right support plate and a top plate to form a door-type support frame. The suspension frame is composed of a suspension rod and a suspension frame. The suspension frame is a U-shaped frame. The bottom end of the suspension rod is fixed to the top center of the suspension frame, and the top end is connected to the longitudinal correction mechanism. The two sides of the suspension frame are connected to the two sides of the body position fixing frame on the treatment bed.

[0020] The transverse correction mechanism includes a transverse slide rail 8, a transverse slider 9, a transverse encoder and a transverse motor. The transverse slide rail is laid on the top surface of the top plate. The transverse slider is configured with the transverse slide rail and slides horizontally along the transverse slide rail. The transverse encoder and the transverse motor are installed on the top plate and are connected through a data line. The transverse encoder is connected to the host through an optical fiber. The transverse motor is connected to the transverse slide rail through a turbine worm mechanism; the longitudinal correction mechanism includes a longitudinal slide rail, a longitudinal slider 10, a longitudinal encoder and a longitudinal motor. The longitudinal slide rail is laid on the inner wall of the central through hole of the transverse slider. The longitudinal slider is configured with the longitudinal slide rail and slides vertically along the longitudinal slide rail. The longitudinal encoder and the longitudinal motor are installed on the top plate and are connected through a data line. The longitudinal encoder is connected to the host through an optical fiber. The longitudinal motor is connected to the longitudinal slide rail through a turbine worm mechanism, and the top of the suspension rod is connected to the bottom surface of the longitudinal slide rail.

[0021] The commands of the central control system are transmitted through optical fiber, and the lateral and longitudinal encoders receive the commands, which are then transmitted to the lateral and longitudinal motors through the data transmission line. The lateral and longitudinal motors receive the commands and start to rotate and drive the lateral and longitudinal sliders to move on the slide rails, driving the movement of the suspension frame, and the body position fixation frame follows the movement, which plays a role in correcting the tilt angle α caused by the correction settlement and the PITCH and YAW angle errors after image registration.

[0022] The angle monitor is a digital tilt angle measuring instrument or a gyroscope.

[0023] The correction frame is made of high molecular carbon fiber composite material, which is not easy to deform and has good stability.

[0024] The top plate is a hollow shell structure. The transverse encoder, transverse motor, longitudinal encoder and longitudinal motor are all arranged in the internal cavity of the top plate and hidden inside the shell. The appearance is simple and beautiful.

[0025] like Figure 2 , Figure 3As shown in the figure, when in use, the longitudinal correction system controls the longitudinal slider to move along the Z axis, increases the height of the position fixation frame, eliminates the α angle caused by the settlement, and a YAW angle may be generated during the bed entry process. The transverse correction system controls the transverse slider to move along the X axis for correction. The purpose is to ensure that the patient's position and tumor target area are consistent with the radiotherapy position of the virtual isocenter and the machine isocenter (refer to the external contour correction system error). After the MVCT is taken and registered with the planned image, there is also a position error (refer to the internal tumor or target area correction random error). At this time, the transverse and longitudinal correction systems can correct the PITCH and YAW angle errors after image registration, which cannot be corrected by the current spiral tomography radiotherapy system. The maximum sliding range of the longitudinal corrector slide in the Z axis direction is 0 to 3 cm, and the maximum sliding range of the transverse corrector slide in the X axis direction is ±2 cm, and the accuracy is 0.1 mm.

Claims

1. A correction system for the settlement of a treatment bed in a helical tomotherapy system, characterized in that: It includes an angle error sensing system, an angle error correction system and a central control system. The angle error sensing system is an angle monitor, which is installed on the head side of the body position fixing frame; the angle error correction system consists of a correction frame, a lateral correction mechanism and a longitudinal correction mechanism. The correction frame is installed on the treatment bed surface, and the lateral and longitudinal correction mechanisms are both arranged on the top surface of the correction frame; the central control system consists of a host, a display and a console. The host is connected to the angle monitor, receives and processes data and transmits it to the display for real-time display. The console is connected to the host, transmits the correction command to the lateral correction mechanism and the longitudinal correction mechanism to control the movement correction; the correction frame includes a fixed frame and a suspension frame. The fixed frame is composed of a left and right base, a left and right support plate and a top plate to form a door-shaped support frame. The suspension frame is composed of a suspension rod and a suspension frame, which is a U-shaped frame. The bottom end of the suspension rod is fixed to the top center of the suspension frame, and the top end is connected to the longitudinal correction mechanism. The two sides of the suspension frame are connected to the two sides of the body position fixing frame on the treatment bed; the transverse correction mechanism includes a transverse slide rail, a transverse slider, a transverse encoder and a transverse motor. The transverse slide rail is laid on the top surface of the top plate, and the transverse slider is configured with the transverse slide rail to slide horizontally along the transverse slide rail. The transverse encoder and the transverse motor are installed on the top plate; the longitudinal correction mechanism includes a longitudinal slide rail, a longitudinal slider, a longitudinal encoder and a longitudinal motor. The longitudinal slide rail is laid on the inner wall of the central through hole of the transverse slider. The longitudinal slider is configured with the longitudinal slide rail to slide vertically along the longitudinal slide rail. The longitudinal encoder and the longitudinal motor are installed on the top plate.

2. The correction system for the settlement of the treatment bed of the helical tomotherapy system according to claim 1, characterized in that: The transverse encoder and the transverse motor are connected via a data line, the transverse encoder is connected to the host via an optical fiber, and the transverse motor is connected to the transverse slider via a worm gear mechanism; the longitudinal encoder and the longitudinal motor are connected via a data line, the longitudinal encoder is connected to the host via an optical fiber, the longitudinal motor is connected to the longitudinal slider via a worm gear mechanism, and the top end of the suspension rod is connected to the bottom surface of the longitudinal slider.

3. The correction system for the settlement of the treatment bed of the helical tomotherapy system according to claim 1, characterized in that: The angle monitor is a digital tilt angle measuring instrument or a gyroscope.

4. The correction system for the settlement of the treatment bed of the helical tomotherapy system according to claim 1, characterized in that: The correction frame is made of high molecular carbon fiber composite material.

5. The correction system for the settlement of the treatment bed of the helical tomotherapy system according to claim 3, characterized in that: The control console consists of a data keyboard, movement buttons and an emergency switch.

6. The correction system for the settlement of the treatment bed of the helical tomotherapy system according to claim 3, characterized in that: The top plate is a hollow shell structure, and the transverse encoder, transverse motor, longitudinal encoder and longitudinal motor are all arranged in the inner cavity of the top plate.

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