WO2020132969A1

WO2020132969A1 - Positioning method and apparatus, and radiotherapy system

Info

Publication number: WO2020132969A1
Application number: PCT/CN2018/124001
Authority: WO
Inventors: 李金升; 付凯强
Original assignee: 西安大医集团股份有限公司
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2020-07-02
Also published as: CN111615413B; CN111615413A

Abstract

Provided are a positioning method and apparatus, and a radiotherapy system, wherein same relate to the technical field of radiotherapy. According to the method, second coordinates of a treatment table when a target point of an affected part coincides with a device isocenter at a Gamma angle for treatment are calculated according to first coordinates of the treatment table acquired when a pre-set X-ray taking point coincides with an imaging point, first relative positions of the imaging point and the device isocenter, second relative positions of the imaging point and a central point of a rotation axis of the Gamma angle, and third relative positions of the target point and the central point of the rotation axis of the Gamma angle at the Gamma angle for treatment, and the position of the treatment table is adjusted according to the second coordinates. Therefore, after the Gamma angle is adjusted during radiotherapy, the second coordinates of the treatment table when the target point coincides with the device isocenter at the adjusted Gamma angle can be accurately calculated, such that the precision of the alignment of the target point and the device isocenter at different Gamma angles can be improved, which can in turn improve the precision of the radiotherapy.

Description

Positioning method, device and radiotherapy system

Technical field

The invention relates to the technical field of radiotherapy, in particular to a positioning method, device and radiotherapy system.

Background technique

Before radiotherapy, an image guidance system (Image Guiding System, IGS) can be used to accurately position the patient under image guidance. During the positioning, the images obtained by the IGS system can be reconstructed with the corresponding digitally reconstructed radiographic (DRR) images reconstructed from the pre-acquired computerized tomography (CT) images of the affected part. Image registration is performed based on the image information to determine the positioning deviation. Then, the patient can be accurately positioned by adjusting the position of the treatment bed. During radiotherapy, you can determine the isocenter of the device based on the relative positional relationship between the imaging point and the isocenter of the device (that is, the beam focus of the ray source), and the relative positional relationship between the preset filming point and the target point in the CT reconstructed image The relative position relationship between the point and the target point, and finally the position of the treatment bed can be adjusted according to the relative position relationship between the isocenter of the device and the target point, so that the target point of the affected part is aligned with the isocenter of the device for the purpose of Radiation Therapy.

In the related art, during radiation therapy, in order to avoid the influence of the treatment beam on sensitive tissues or organs (such as the eyes) outside the affected part, the patient’s posture is generally adjusted by adjusting the gamma angle of the radiation therapy system, so that the treatment The beam can avoid sensitive parts. Wherein, the gamma angle may refer to the angle between the support surface of the gamma angle adjusting device at the bottom of the patient and the vertical surface for supporting the patient.

However, because patients take CT images, they are usually taken lying down, that is, the gamma angle is fixed at 90 degrees. If the gamma angle is adjusted during the course of radiotherapy, the accuracy of the IGS system when positioning according to the reconstructed image of the CT image will be significantly lower, seriously affecting the effect of radiotherapy.

Summary of the invention

The invention provides a positioning method, device and radiation therapy system, which can solve the problem of low accuracy of the positioning method in the related art. The technical solution is as follows:

In a first aspect, a positioning method is provided. The method includes:

Obtain the gamma angle to be treated;

Acquiring the first coordinates of the treatment bed, where the first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS;

Acquiring the first relative position of the imaging point and the isocenter of the device;

Acquiring the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, the center point of the rotation axis of the gamma angle being the center point of the rotation axis of the gamma angle of the gamma angle adjustment device for adjusting the gamma angle ;

Acquiring the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated;

According to the first coordinate, the first relative position, the second relative position and the third relative position, calculate the isocenter of the target and the device under the gamma angle to be treated When the points coincide, the second coordinate of the treatment bed;

The position of the treatment bed is adjusted according to the second coordinate.

Optionally, before acquiring the first coordinates of the treatment bed, the method further includes:

Acquiring a reconstructed image of the gamma angle to be treated, the reconstructed image being an image reconstructed according to an electronic image of the affected part acquired in advance;

Acquiring an IGS image of the affected part under the gamma angle to be treated, the IGS image being an image generated by the image guidance system;

The image registration of the reconstructed image and the IGS image is performed by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.

Optionally, the acquiring the second relative position of the imaging point and the center point of the rotation axis of the gamma angle includes: acquiring the imaging point and the rotation axis of the gamma angle when the treatment bed is at the initial position The initial relative position of the center point;

The difference between the initial relative position and the first coordinate is determined as the second relative position.

Optionally, the acquiring the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated includes:

Acquiring the target relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees, the target relative position includes: the target point and the gamma The first target relative distance in the width direction of the treatment bed, the second target relative distance in the length direction of the treatment bed, and the third target height in the height direction of the treatment bed Relative target distance

According to the relative distance of the second target and the relative distance of the third target, it is determined that when the gamma angle to be treated is 90 degrees, the center point of the target point and the rotation axis of the gamma angle is in the first plane Within the first distance, the first plane is the plane where the first axis extends along the length of the treatment bed and the second axis extends along the height of the treatment bed;

Determine the first gamma angle according to the relative distance of the second target and the relative distance of the third target;

The third relative position is calculated according to the first target relative distance, the first gamma angle, the gamma angle to be treated, and the first distance.

Optionally, the third relative position includes: under the gamma angle to be treated, a first relative position of the target point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed Distance, a second relative distance in the length direction of the treatment bed, and a third relative distance in the height direction of the treatment bed;

The calculating the third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated and the first distance includes:

Determining the first target relative distance as the first relative distance;

The product of the first distance and the cosine value of the first angle is determined as the second relative distance, and the first angle is to add the first gamma angle to 90 degrees, and then to the treatment The angle obtained by subtracting the gamma angle of

The product of the first distance and the sine value of the first angle is determined as the third relative distance.

Optionally, the acquiring the relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees includes:

When the gamma angle to be treated is 90 degrees, obtain a fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle;

When the gamma angle to be treated is 90 degrees, obtain a fifth relative position of the target point and the imaging point;

The sum of the fourth relative position and the fifth relative position is determined as the target relative position.

Optionally, the second relative position includes: a first length of the imaging point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, and a length in the length direction of the treatment bed A second length, and a third length in the height direction of the treatment bed;

The acquiring the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees includes:

Calculating the second distance between the imaging point and the center point of the rotation axis of the gamma angle in the first plane under the gamma angle to be treated according to the second length and the third length ;

Determine the second gamma angle according to the second length and the third length;

The fourth relative position is calculated according to the first length, the second gamma angle, the gamma angle to be treated, and the second distance.

Optionally, the fourth relative position includes: when the gamma angle to be treated is 90 degrees, the imaging point and the center point of the gamma angle rotation axis are in the width direction of the treatment bed A first position, a second position in the length direction of the treatment bed, and a third position in the height direction of the treatment bed;

The calculating the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance includes:

Determining the first length as the first position;

The product of the second distance and the cosine value of the second angle is determined as the second position, the second angle is the sum of the second gamma angle and 90 degrees, and then combined with the to-be-treated The angle obtained by subtracting the gamma angle;

The product of the second distance and the sine value of the second angle is determined as the third position.

Optionally, the target point is calculated under the gamma angle to be treated according to the first coordinate, the first relative position, the second relative position and the third relative position When it coincides with the isocenter of the device, the second coordinate of the treatment bed includes:

Adding the first coordinate and the first relative position to subtract the third relative position, and then adding the second relative position to obtain the second coordinate of the treatment bed.

In a second aspect, a positioning device is provided. The device includes:

The first acquisition module is used to acquire the gamma angle to be treated;

The second acquisition module is used to acquire the first coordinates of the treatment bed, where the first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS;

A third acquisition module, configured to acquire the first relative position of the imaging point and the isocenter of the device;

A fourth obtaining module, configured to obtain the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, the center point of the rotation axis of the gamma angle is the gamma of the gamma angle adjusting device for adjusting the gamma angle The center point of the rotation axis of the Mayer;

A fifth acquisition module, configured to acquire a third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated;

The calculation module is configured to calculate the target point and the target angle under the gamma angle to be treated according to the first coordinate, the first relative position, the second relative position and the third relative position When the isocenter of the device coincides, the second coordinate of the treatment bed;

The first adjustment module is used to adjust the position of the treatment bed according to the second coordinate.

Optionally, the device further includes:

A sixth acquisition module, configured to acquire a reconstructed image of the gamma angle to be treated before acquiring the first coordinates of the treatment bed, the reconstructed image being an image reconstructed from an electronic image of the affected part acquired in advance;

A seventh acquisition module, configured to acquire an IGS image of the affected part under the gamma angle to be treated, the IGS image being an image generated by the image guidance system;

The second adjustment module is used to perform image registration of the reconstructed image and the IGS image by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.

Optionally, the fourth obtaining module is used to:

Acquiring the initial relative position of the imaging point and the center point of the rotation axis of the gamma angle when the treatment bed is at the initial position;

Optionally, the fifth obtaining module includes:

An acquisition sub-module for acquiring the relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees, the target relative position includes: the target The relative distance between the point and the first target in the width direction of the treatment bed of the center point of the rotation axis of the gamma angle, the relative distance of the second target in the length direction of the treatment bed, and the The relative distance of the third target in the height direction;

A first determining submodule, configured to determine the target point and the gamma angle when the gamma angle to be treated is 90 degrees according to the relative distance between the second target and the third target A first distance of the center point of the rotation axis in a first plane, where the first plane is a plane where a first axis extending along the length of the treatment bed and a second axis extending along the height of the treatment bed are located ;

A second determining submodule, configured to determine the first gamma angle according to the relative distance of the second target and the relative distance of the third target;

The calculation submodule is configured to calculate the third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated, and the first distance.

The calculation submodule is used for:

Determining the first target relative distance as the first relative distance;

Optionally, the obtaining submodule is used to:

The acquiring submodule acquiring the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle includes:

The obtaining submodule calculating the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance includes:

Determining the first length as the first position;

Optionally, the calculation module is used to:

In a third aspect, a positioning device is provided. The device includes:

A processor and a memory, and the memory stores instructions, and the instructions are loaded and executed by the processor to implement the positioning method according to the first aspect.

According to a fourth aspect, a storage medium is provided, in which instructions are stored in the storage medium, and when the storage medium runs on a processing component, the processing component is caused to execute the positioning method as described in the first aspect.

According to a fifth aspect, there is provided a radiation therapy system. The radiation therapy system includes the positioning device according to the second aspect.

In summary, the embodiments of the present invention provide a positioning method, device, and radiotherapy system. The method can be based on the first coordinate of the treatment bed obtained when the preset filming point coincides with the imaging point, the first relative position of the imaging point and the isocenter of the device, and the second of the imaging point and the center point of the rotation axis of the gamma angle Relative position, and the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated. Calculate when the target point coincides with the isocenter of the device under the gamma angle to be treated The second coordinate of the treatment bed, and adjust the position of the treatment bed according to the second coordinate. Therefore, when the gamma angle is adjusted during the radiotherapy process, the second coordinate of the treatment bed can be calculated accurately when the target point coincides with the isocenter of the device under the adjusted gamma angle. Improve the alignment accuracy of the target point and the isocenter of the device at different gamma angles, which can improve the accuracy of radiotherapy.

It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present invention.

BRIEF DESCRIPTION

In order to more clearly explain the technical solutions in the embodiments of the present invention, the drawings required in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For a person of ordinary skill in the art, without paying any creative work, other drawings can be obtained based on these drawings.

1 is a schematic structural diagram of a radiation therapy system provided by an embodiment of the present invention;

2 is a front view of a gamma angle adjustment device provided by an embodiment of the present invention;

3 is a flowchart of a positioning method provided by an embodiment of the present invention;

4 is a flowchart of another positioning method provided by an embodiment of the present invention;

5 is a schematic diagram of a CT reconstructed image including a target point and a preset filming point, which is provided by an embodiment of the present invention;

6 is a flowchart of a method for determining a third relative position provided by an embodiment of the present invention;

7 is a side view of a gamma angle adjustment device provided by an embodiment of the present invention;

8 is a side view of another gamma angle adjustment device provided by an embodiment of the present invention;

9 is a block diagram of a positioning device provided by an embodiment of the present invention;

10 is a block diagram of another positioning device provided by an embodiment of the present invention;

11 is a block diagram of a fifth acquisition module provided by an embodiment of the present invention.

Through the above drawings, a definite embodiment of the present invention has been shown, which will be described in more detail later. These drawings and text description are not intended to limit the scope of the inventive concept in any way, but to explain the concept of the present invention to those skilled in the art by referring to specific embodiments.

detailed description

To make the objectives, technical solutions, and advantages of the present invention clearer, the following describes the embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a radiation therapy system provided by an embodiment of the present invention. As shown in FIG. 1, the radiotherapy system may include an image guidance system 01, a host computer 02, a treatment bed 03, and a treatment rack 04. The host computer 02 may establish a communication connection with the image guidance system 01 and the treatment bed 03.

Wherein, the host computer 02 may be a control device in a treatment control system, and the image guidance system 01 may be an IGS system. The IGS system 01 may include one or more sets of image acquisition components, and each set of image acquisition components may include a relatively arranged detector 011 and a bulb 012 (FIG. 1 only shows a relatively arranged set of detector 011 and a bulb. 012), the bulb 012 can emit radiation (for example, X-rays), the detector 011 can be a flat panel detector, and the detector 011 can receive the radiation emitted by the bulb 012. The IGS system 01 can generate an IGS image based on the radiation received by each detector 011. When the IGS system 01 includes a set of image acquisition components, the relatively arranged detector 011 and bulb 012 can be rotated to multiple positions and produce IGS images at multiple positions, respectively. In the embodiment of the present invention, taking the IGS system 01 including multiple sets of image acquisition components as an example, for example, two sets of image acquisition components, the rays emitted by the bulb 012 in the multiple sets of image acquisition components in the IGS system 01 may intersect at one point , This point is the imaging point A1 of the IGS system. The treatment rack 04 may be provided with a plurality of ray sources 041, and the plurality of ray sources 041 may all be γ-ray sources (that is, the plurality of ray sources 041 may all emit γ rays), or they may all be X-ray sources (That is, the multiple radiation sources 041 can all emit X-rays). In addition, the treatment beams emitted by the plurality of radiation sources 041 may intersect at a point, which is the beam focus (which may also be referred to as the isocenter of the device) A2.

Before performing radiation therapy, a CT scan is usually performed on the patient to obtain a CT image of the affected part, and a CT reconstructed image is obtained based on the CT image. Of course, before radiation therapy, you can also perform MR scan on the patient to obtain MR images of the patient. The embodiments of the present invention take CT as an example for illustration. The treating physician can formulate a treatment plan for the affected part based on the size, shape and surrounding tissue of the affected part tumor displayed in the CT reconstructed image, and input the treatment plan to the host computer 02. After that, the host computer 02 can drive the treatment bed 03 to move the affected part of the patient to the imaging area of the IGS system 01 to acquire images. Then, by comparing the IGS image acquired by the IGS system 01 with the pre-acquired CT reconstructed image, you can determine the preset filming point in the CT reconstructed image (that is, a predetermined fixed point in the CT reconstructed image) and the IGS system 01 The relative position of the imaging point A1.

Further, the host computer 02 can adjust the position of the treatment bed 03 so that the preset filming point coincides with the imaging point A1 of the IGS system 01. When performing radiotherapy, the host computer 02 can determine the target point A3 and the relative positional relationship between the preset point in the CT reconstructed image and the target point A3 according to the relative position relationship between the isocenter A2 of the device and the imaging point A1 The positional relationship between the isocenter A2 of the device, and adjust the position of the treatment bed 03 according to the positional relationship, so that the target point A3 is aligned with the isocenter A2 of the device, so as to realize the positioning of the patient.

However, since the patient is generally lying on the treatment bed 03 when performing CT positioning scan on the patient, the treatment beam may pass through the patient's sensitive tissues or organs, such as the eyes, to illuminate the target A3. Therefore, as shown in FIG. 1, the treating physician can adjust the patient's position through the gamma angle adjustment device 031 and so on, so that the treatment beam avoids sensitive tissues or organs, and the gamma angle adjustment device 031 can bypass the fixed gamma The Mayer axis of rotation rotates in a vertical plane, for example, it can rotate in the YOZ plane shown in FIG. 1. The axis of the rotation axis of the gamma angle is parallel to the horizontal plane and perpendicular to the length direction of the treatment bed 03. Wherein, the angle γ between the support surface n of the support portion for supporting the patient and the vertical plane m in the gamma angle adjusting device 031 can be called a gamma angle.

FIG. 2 is a front view of a gamma angle adjusting device 031 provided by an embodiment of the present invention. Referring to FIG. 2, it can be seen that the gamma angle adjusting device 031 may include a fixing frame 31a and a supporting frame 31b. The fixing frame 31a may be fixed on the treatment bed 03, and the supporting frame 31b is rotatably connected to the fixing frame 31a. For example, the axis L shown in FIG. 2 may be the gamma angle rotation axis of the gamma angle adjustment device 031, and correspondingly, the point A4 may be the center point of the gamma angle rotation axis of the gamma angle rotation axis L . The embodiment of the present invention does not limit the specific structure of the gamma angle adjusting device 031, and only uses the example shown in FIG. 2 as an example for description.

Exemplarily, the CT image is scanned when the patient is lying down (that is, the gamma angle γ is 90°). In the actual treatment process, if the treating physician chooses a 70° gamma angle treatment, when using the IGS system 01 for positioning, it is necessary to adjust the head gamma angle adjustment device 031 so that the patient is at a 70° gamma angle , And then acquire IGS images. At this time, if the CT reconstructed image and the IGS image obtained are directly compared, the offset cannot be obtained due to the different deflection angles of the patient's posture, and accurate treatment cannot be achieved. Therefore, when the gamma angle is adjusted during the radiotherapy process, the position under the gamma angle needs to be considered, that is, the coordinates of the treatment bed under the gamma angle need to be considered to ensure that The accuracy of the swing position at different gamma angles can ensure the accuracy of radiotherapy.

The embodiment of the present invention provides a positioning method, which can calculate the coordinates of the treatment bed 03 when the target point A3 coincides with the isocenter A2 of the device at different gamma angles. After the gamma angle changes, the host computer 02 can also accurately adjust the position of the treatment bed 03 according to the calculated coordinates of the treatment bed 03, and improve the alignment accuracy of the target point A3 and the isocenter A2 of the device, thereby improving the radiation The accuracy of treatment.

3 is a flowchart of a positioning method provided by an embodiment of the present invention. The positioning method can be applied to the host computer 02 shown in FIG. 1, and as shown in FIG. 3, the method can include:

Step 301: Obtain the gamma angle to be treated.

In the embodiment of the present invention, the gamma angle to be treated may refer to the current gamma angle to be treated.

For example, the treating physician can fix the patient to a certain gamma angle through the gamma angle adjusting device 031, and input the current gamma angle to the upper computer 02, that is, the upper computer 02 can obtain the input of the treating physician to be treated Gamma angle γ. Or when the treating physician fixes the patient to a certain gamma angle through the gamma angle adjusting device 031, the upper computer 02 can automatically detect the gamma angle γ to be treated. Alternatively, the host computer 02 can also determine the gamma angle γ to be treated according to the treatment plan obtained in advance. The embodiment of the present invention does not limit the manner in which the host computer 02 obtains the gamma angle to be treated.

Step 302: Obtain the first coordinates of the treatment bed. The first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS.

For example, the host computer 02 can acquire a CT reconstructed image under the gamma angle to be treated. The CT-created image may be an image reconstructed by the IGS system 01 based on the electronic image (eg, CT image) of the affected part acquired in advance and sent to the host computer 02, and the CT reconstructed image may include a preset filming point. After that, when the host computer 02 drives the treatment bed 03 to send the affected part of the patient into the imaging area (ie, the filming area), the IGS system 01 can acquire the IGS image of the affected part of the patient, and send the acquired IGS image to the host computer 02.

In order to determine whether the preset filming point coincides with the imaging point A1, the host computer 02 can perform image registration on the acquired IGS image and CT reconstructed image, and can continuously adjust the position of the treatment bed 03 during the registration process. The preset shooting point coincides with the imaging point A1. When the preset filming point coincides with the imaging point, the host computer 02 can obtain the first coordinate of the treatment bed 03 at this time.

Step 303: Acquire the first relative position of the imaging point and the isocenter of the device.

In the radiotherapy system, the positions of the imaging point A1 and the center point A2 of the device are fixed, and the imaging point A1 and the center point A2 of the device are located in the coordinate system where the treatment bed 03 is located (also can be called the device Coordinate system), so the IGS system 01 can directly obtain the position coordinates of the imaging point A1 and the center point A2 of the device, and calculate the imaging point A1 and the device according to the obtained position coordinates of the imaging point A1 and the center point A2 of the device The first relative position of the center point A2.

Step 304: Acquire a second relative position of the imaging point and the center point of the rotation axis of the gamma angle.

In the embodiment of the present invention, the gamma angle rotation axis center point A4 may be the center point of the gamma angle rotation axis L of the gamma angle adjustment device 031 for adjusting the gamma angle. Since the position of the center point A4 of the rotation axis of the gamma angle is also fixed, and the center point A4 of the rotation axis of the gamma angle is also located in the device coordinate system, the IGS system can directly obtain the position coordinates of the center point A4 of the rotation axis of the gamma angle And calculate the second relative position of the imaging point A1 and the gamma angle rotation axis center point A4 according to the acquired position coordinates of the imaging point A1 and the gamma angle rotation axis center point A4.

Step 305: Obtain the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated.

In the embodiment of the present invention, the host computer 02 may determine the position of the target point A3 under the gamma angle to be treated according to the treatment plan.

For example, before radiotherapy, the host computer 02 can acquire CT reconstruction images at different gamma angles to be treated, and the treating physician can formulate a treatment plan including the target A3 position for the patient based on the CT reconstruction image and input To the host computer 02, and then the host computer 02 can obtain the position of the target point A3 from the treatment plan. Since the target point A3 and the center point A4 of the gamma rotation axis are in different coordinate systems, the host computer 02 can also convert the positions of the target point A3 and the center point A4 of the gamma rotation axis to the same coordinate system. Furthermore, the third relative position of the target point A3 and the center point A4 of the rotation axis of the gamma angle is calculated.

Step 306: According to the first coordinate, the first relative position, the second relative position, and the third relative position, calculate the second coordinate of the treatment bed when the target point coincides with the isocenter of the device under the gamma angle to be treated.

After the host computer 02 obtains the first coordinate, the first relative position, the second relative position, and the third relative position, it can accurately determine the first coordinate, the first relative position, the second relative position, and the third relative position. The second coordinate of the treatment bed is calculated when the target point coincides with the isocenter of the device at the gamma angle to be treated.

Step 307: Adjust the position of the treatment bed according to the second coordinate.

Further, the host computer 02 can accurately adjust the position of the treatment bed 03 according to the calculated second coordinates. The alignment accuracy of the target point A3 and the equipment isocenter A2 under the gamma angle to be treated is improved, thereby further improving the accuracy of radiotherapy.

In summary, the embodiment of the present invention provides a positioning method, which can be based on the first coordinate of the treatment bed obtained when the preset filming point coincides with the imaging point, the first point of the imaging center and the isocenter of the device, etc. A relative position, the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, and the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated, calculated at Under the gamma angle to be treated, the second coordinate of the treatment bed when the target point coincides with the isocenter of the device, and the position of the treatment bed is adjusted according to the second coordinate. Therefore, when the gamma angle is adjusted during the radiotherapy process, the second coordinate of the treatment bed can be calculated accurately when the target point coincides with the isocenter of the device under the adjusted gamma angle. Improve the alignment accuracy of the target point and the isocenter of the device at different gamma angles, which can improve the accuracy of radiotherapy.

It should be noted that in the embodiment of the present invention, the host computer 02 establishes a communication connection with the IGS system 01 and the treatment bed 03, respectively, and may be performed by the host computer 02 performing the above steps 301-307 as an example. In the actual execution process, The treatment bed 03 and the IGS system 01 may be respectively provided with processors. Correspondingly, the treatment bed 03 and the IGS system 01 may also perform the corresponding steps in the foregoing embodiments through their respective processors. It is not limited, and will be illustrated by taking FIG. 3 and the above embodiments as examples.

FIG. 4 is a flowchart of another positioning method provided by an embodiment of the present invention. This positioning method can be applied to the host computer 02 shown in FIG. 1. Or, referring to the above description, it can be known that the positioning method can also be applied to the IGS system 01 or the treatment bed 03 shown in FIG. 1, which is not limited in the embodiment of the present invention, and the following embodiment uses the positioning method to apply The host computer 02 will be described as an example. As shown in FIG. 4, the method may include:

Step 401: Obtain the gamma angle to be treated.

As an example implementation method: the treating physician fixes the patient at a certain gamma angle through the gamma angle adjusting device 031, and can input the current gamma angle γ to be treated to the upper computer 02, that is, the upper computer 02 can obtain The gamma angle γ to be treated input by the treating physician is relatively reliable.

As another example of implementation: when the therapist fixes the patient to a certain gamma angle through the gamma angle adjustment device 031, the host computer 02 can automatically detect the gamma angle γ to be treated, the efficiency of the acquisition method Higher.

As yet another example implementation, the host computer 02 may determine the gamma angle γ to be treated according to the treatment plan acquired in advance.

For example, assuming that the current gamma angle γ to be treated is 70°, the treating physician can adjust the gamma angle adjustment device 031 shown in FIG. 1 so that the gamma angle γ is 70°. After fixing the gamma angle adjusting device 031, the treating physician can input the current gamma angle γ to be treated to the upper computer 02 as γ=70 ^° , and then the upper computer 02 can obtain the gamma angle γ to be treated as: 70°.

Step 402: Acquire a reconstructed image of the gamma angle to be treated.

In the embodiment of the present invention, the reconstructed image may be an image reconstructed from an electronic image (eg, CT image) of the affected part acquired in advance. And the reconstructed image may be an image reconstructed by the IGS system 01 based on the electronic image. Alternatively, the reconstructed image may also be an image reconstructed by the electronic image generating device (for example, CT device) according to the electronic image. Alternatively, the reconstructed image may also be a reconstructed image generated by another image processing system based on the electronic image. The embodiment of the present invention does not limit the device that generates the reconstructed image.

Exemplarily, the reconstructed image may be a digitally reconstructed radiographic DRR image, and the DRR image may be an image reconstructed from the CT image of the IGS system 01 after acquiring the CT image of the affected part. Correspondingly, the reconstructed image can also be called CT-DRR slice. And referring to FIG. 5, the CT-DRR film may include: the positions of the target point A3 and the preset filming point A5. FIG. 5 shows a CT-DRR film including two target points A3.

For example, the electronic image acquired by the IGS system 01 may be a plurality of continuous tomographic images obtained by scanning the affected part with a CT device, that is, the electronic image may be a set of image sequences. Each tomographic image in the image sequence is perpendicular to the horizontal axis of the treatment bed 03, and the extending direction of the horizontal axis may be parallel to the movement direction (ie, the advancing direction) of the treatment bed 03 when it moves closer to the treatment chamber. Since each tomographic image is a two-dimensional image, the multiple consecutive tomographic images can be reconstructed into three-dimensional volume data of the affected part by computer processing. Exemplarily, the CT device can scan the affected part with a layer thickness of no more than 2 mm and no layer spacing.

In the process of reconstructing the image, the IGS system 01 can first determine the rotation axis according to the preset filming point A5 in the CT image, which can be the specified coordinate axis of the coordinate system where the filming point A5 is located, or parallel to the specified coordinate axis Linear axis. For example, in the coordinate system where the filming point A5 is located, a linear axis passing through the filming point A5 and parallel to the specified coordinate axis (for example, X axis) may be determined as the rotation axis. Further, for each gamma angle, the IGS system 01 can rotate the CT image by a deflection angle with the rotation axis as an axis, so as to reconstruct the reconstructed image of the gamma angle. The deflection angle is the deflection angle between the gamma angle and the initial gamma angle when acquiring the electronic image. Specifically, the IGS system 01 can rotate the three-dimensional volume data corresponding to the multiple tomographic images by the deflection angle about the rotation axis, and project the rotated three-dimensional volume data to the IGS according to the installation parameters of the IGS system 01 The virtual imaging plane of the system 01 to obtain the reconstructed image of the gamma angle.

The filming point A5 in the CT image is a preset point in the CT image, and the position of the filming point A5 can be described by the coordinates of three coordinate axes in the three-dimensional coordinate system where the filming point A5 is located. The virtual imaging surface is the imaging surface of the IGS system 01 virtually constructed in the coordinate system where the filming point A5 is located. The position of the virtual imaging surface in the three-dimensional coordinate system where the filming point A5 is located is the same as that of the detector in the IGS system 01 The imaging plane has the same position in the coordinate system (also referred to as device coordinate system) where the treatment bed 03 is located.

For example, as described above, the IGS system 01 may include: multiple sets of image acquisition components, and each set of image acquisition components may include a detector 011 and a tube 012 that are relatively disposed. Since the installation parameters of each group of image acquisition components will affect the virtual imaging surface of the IGS system 01 when generating the reconstructed image, the IGS system 01 will project the rotated three-dimensional volume data onto the virtual imaging surface of the IGS system 01 The position of the virtual imaging surface of the IGS system 01 in the coordinate system where the filming point is located can also be determined according to the installation parameters of the image acquisition component. Wherein, the installation parameters may include: the angle between the rays of the two sets of image acquisition components, the distance between the detector 011 and the bulb 012 in each group of image acquisition components, and the distance between the intersection point of the rays and the detector 011. The radiation of each group of image acquisition components may be the connection between the detector 011 and the bulb 012 in the group of image acquisition components, and the imaging surface of the detector 011 is perpendicular to the radiation emitted by the bulb 012.

It should be noted that when rotating the three-dimensional volume data to reconstruct a reconstruction image of a certain gamma angle, the rotation of the three-dimensional volume data can be determined according to the deflection direction of the gamma angle relative to the initial gamma angle when the CT image is acquired Direction to ensure that the rotation direction of the three-dimensional volume data in the image coordinate system is consistent with the deflection direction of the gamma angle in the coordinate system where the treatment bed 03 is located, and the deflection angle is also consistent.

Further, the IGS system 01 can send the reconstructed CT-DRR slices of multiple gamma angles to the upper computer 02, and after the upper computer 02 obtains the gamma angle to be treated, it can be obtained from at least one gamma angle In the reconstructed image of, the reconstructed image of the gamma angle to be treated is retrieved.

For example, after acquiring the current gamma angle γ to be treated, the host computer 02 may retrieve the reconstructed image of the gamma angle γ to be treated from a plurality of reconstructed images received in advance. For example, the IGS system 01 can reconstruct 60°, 70°, 80°, 90°, 100°, and 110° reconstructed images from the CT images, and send the reconstructed images corresponding to the multiple gamma angles to the host computer 02. If the upper computer 02 acquires the current gamma angle γ to be treated as 70°, it can directly retrieve the reconstructed image of the gamma angle of 70°.

Step 403: Acquire the IGS image of the affected part under the gamma angle to be treated.

The IGS image is an image generated by the image guidance system 01 (that is, the IGS system 01). The host computer 02 can adjust the position of the treatment bed 03 according to the preset fixed coordinate value, and send the affected part of the patient into the imaging area of the IGS system. Since the current patient is already fixed under the gamma angle γ to be treated, the IGS system 01 can directly acquire the IGS image of the affected part under the gamma angle γ to be treated through multiple sets of image acquisition components, and the IGS system 01 can Send the acquired IGS image to the host computer 02.

For example, the host computer 02 can send an imaging instruction to the IGS system 01. After receiving the imaging instruction, the IGS system 01 can control the two bulbs 012 shown in FIG. 2 to emit rays. Correspondingly, the two detections shown in FIG. 2 All the devices 011 can receive the radiation from the bulb 012, and the IGS system 01 can generate an IGS image according to the radiation received by each detector 011, and send it to the host computer 02.

Step 404: Perform image registration of the reconstructed image and the IGS image by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.

In the embodiment of the present invention, in order to determine whether the preset filming point A5 and the imaging point A1 in the reconstructed image (ie, CT-DRR film) coincide, the host computer 02 can perform image registration on the CT-DRR film and the IGS image , And can continuously adjust the position of the treatment bed 03 in the process of image registration. After the image registration, the preset filming point A5 and imaging point A1 are finally made.

Among them, in the process of image registration, one image can usually be designated as the reference image, and the other image is the image to be registered. The purpose of registration is to make the coordinates of all points on the image to be registered and the reference image. All reached consensus.

Step 405: Obtain the first coordinates of the treatment bed. The first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS.

When the preset filming point A5 and the imaging point A1 coincide, the host computer 02 can obtain the first coordinates of the treatment bed 03 at this time. The first coordinate may include a first-dimensional coordinate X1 extending in the width direction of the treatment bed 03, a second-dimensional coordinate Y1 extending in the length direction of the treatment bed 03, and a third dimension extending in the height direction of the treatment bed 03 Coordinate Z1. That is, the first coordinate can be expressed as (X1, Y1, Z1).

Step 406: Acquire the first relative position of the imaging point and the isocenter of the device.

In the radiotherapy system, the positions of the imaging point A1 and the center point A2 of the device are fixed, and the imaging point A1 and the center point A2 of the device are located in the coordinate system where the treatment bed 03 is located (also can be called the device Coordinate system), so the host computer 02 can directly obtain the position coordinates of the imaging point A1 and the center point A2 of the device, and calculate the imaging point A1 and the device according to the obtained position coordinates of the imaging point A1 and the center point A2 of the device The first relative position of the center point A2.

The first relative position may include: a first distance Xiso of the imaging point A1 and the isocenter A2 of the device in the width direction of the treatment bed 03, and a second distance Yiso in the length direction of the treatment bed 03, in the treatment bed The third distance Ziso in the height direction of 03.

For example, the position coordinates of the imaging point A1 acquired by the host computer 02 in the device coordinate system are: (Xi, Yi, Zi), and the position coordinates of the acquired device isocenter A2 in the device coordinate system are: (Xc, Yc, Zc), the host computer 02 can calculate the first relative position (Xiso, Yiso, Ziso) of the imaging point A1 and the isocenter A2 of the device to satisfy: Xiso=Xi-Xc, Yiso=Yi-Yc, Ziso=Zi- Zc.

Exemplarily, the first relative position (Xiso, Yiso, Ziso) may also be obtained through mechanical design or film measurement. The embodiment of the present invention does not limit the manner of obtaining the first relative position.

Step 407: Obtain the second relative position of the imaging point and the center point of the rotation axis of the gamma angle.

In the embodiment of the present invention, the gamma angle rotation axis center point A4 may refer to the center point of the gamma angle rotation axis L of the gamma angle adjusting device 031 for adjusting the gamma angle. The second relative position may also include: a first length Ix of the imaging point A1 and the center point A4 of the rotation axis of the gamma angle in the width direction of the treatment bed 03, a second length Iy in the length direction of the treatment bed 03, and The third length Iz in the height direction of the treatment bed 03, that is, the second relative position can be expressed as (Ix, Iy, Iz).

In the embodiment of the present invention, when the treatment bed 03 is at the initial position (it may also be called that the treatment bed 03 is at the zero point), that is, when the coordinate of the treatment bed 03 is (0, 0, 0), the IGS system 01 may first Acquire the initial relative position of the imaging point A1 and the gamma angle rotation axis center point A4 in the YOZ plane, and determine the difference between the initial relative position and the acquired first coordinates of the treatment bed 03 as the second relative position.

Wherein, the initial relative position may include the initial distance X0 of the imaging point A1 and the center point A4 of the rotation axis of the gamma angle in the width direction of the treatment bed 03, the initial distance Y0 in the length direction of the treatment bed 03, and the treatment bed 03 The initial distance Z0 in the height direction. That is, the initial relative position can be expressed as: (X0, Y0, Z0), for example, the initial relative position (X0, Y0, Z0) can be (-0.55, 138.79, -1.98). The first coordinate may include a first-dimensional coordinate X1 extending in the width direction of the treatment bed 03, a second-dimensional coordinate Y1 extending in the length direction of the treatment bed 03, and a third three-dimensional coordinate Z1 extending in the height direction of the treatment bed 03 . That is, the first coordinate can be expressed as: (X1, Y1, Z1). Correspondingly, the second relative position (Ix, Iy, Iz) of the imaging point A1 and the gamma angle rotation axis center point A4 determined by the host computer 02 can satisfy: Ix=X0-X1, Iy=Y0-Y1, Iz= Z0-Z1.

Step 408: Acquire a third relative position between the target point of the affected part under the gamma angle to be treated and the center point of the rotation axis of the gamma angle.

In the embodiment of the present invention, the host computer 02 may first determine the position of the affected target A3 according to the treatment plan.

For example, before radiotherapy, the host computer 02 can obtain CT reconstruction images at different gamma angles to be treated, and the treating physician can formulate a treatment plan including the target A3 position for the patient based on the CT reconstruction image and input To the host computer 02, and then the host computer 02 can obtain the position of the target point A3 from the treatment plan. For example, the host computer 02 can obtain a CT-DRR slice whose gamma angle γ to be treated is 70°, 90°, or 110°. Secondly, since the position of the center point A4 of the rotation axis of the gamma angle is fixed, the host computer 02 can also directly obtain the position of the center point A4 of the rotation axis of the gamma angle. Since the target point A3 and the center point A4 of the gamma rotation axis are in different coordinate systems, the host computer 02 can also convert the positions of the target point A3 and the center point A4 of the gamma rotation axis to the same coordinate system. From the calculation, the third relative position of the target point A3 and the center point A4 of the rotation axis of the gamma angle is obtained.

6 is a flowchart of a method for determining a third relative position provided by an embodiment of the present invention. This method can be applied to the host computer 02 shown in FIG. 1. As shown in FIG. 6, the method may include:

Step 4081: Acquire the relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees.

In the embodiment of the present invention, the relative position of the target may include: a first target relative distance Tx90 of the target point A3 and the center point A4 of the rotation axis of the gamma angle in the width direction of the treatment bed 03, and in the length direction of the treatment bed 03 The second target is the relative distance Ty90, and the third target in the height direction of the treatment bed 03 is the relative distance Tz90. That is, the relative position of the target can be expressed as (Tx90, Ty90, Tz90).

Illustratively, an embodiment of the present invention provides a method for acquiring the relative position of the target A3 and the center point A4 of the rotation axis of the gamma angle when the gamma angle γ to be treated is 90 degrees:

Step S1: When the gamma angle to be treated is 90 degrees, obtain a fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle.

The embodiment of the present invention provides a method for obtaining the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees:

Step S10: Calculate the second distance between the imaging point and the center point of the rotation axis of the gamma angle in the first plane under the gamma angle to be treated according to the second length and the third length.

Wherein, the first plane may be the plane where the third axis Z extending along the length direction of the treatment bed and the second axis Y extending along the height direction of the treatment bed, that is, the YOZ plane shown in FIG. 1.

7 and 8 are side views of a gamma angle adjusting device 031 provided by an embodiment of the present invention. 7 and 8, it can be seen that the support frame 31b may include a support panel b1 for supporting the affected part (eg, head) of the patient, and two oppositely disposed connecting rods b2, one end of each connecting rod b2 is connected to the The support panel b1 is fixedly connected, and the other end is rotatably connected to the fixing frame 31a. Comparing FIGS. 7 and 8, it can be seen that the connecting rod b2 can drive the support panel b1 to rotate in the vertical plane, that is, the YOZ plane, so that the gamma angle γ can be adjusted.

According to the above analysis, since the gamma angle adjusting device 031 can only rotate in the first plane YOZ, that is, in the process of adjusting the gamma angle, the position of the target point A3 changes only in the first plane YOZ, the The coordinates of the target point A3 on the first axis X will not change, so after the host computer 02 calculates the second relative position (Ix, Iy, Iz), it can first calculate according to the second length Iy and the third length Iz in the angle gamma to be treated, imaging points A1 and A4 gamma angular rotation shaft center point distance of the second LI in the YOZ plane _YOZ, the second distance LI _YOZ satisfy:

Step S11: Determine the second gamma angle according to the second length and the third length.

In the embodiment of the present invention, the second gamma angle γ2 determined by the host computer 02 according to the second length Iy and the third length Iz may satisfy: γ2=arctan(Iz/Iy), that is, the second gamma angle γ2 may be The arc tangent of the ratio of the third length Iz to the second length Iy.

Step S12: Calculate the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance.

In the embodiment of the present invention, the fourth relative position may include: when the gamma angle γ to be treated is 90 degrees, the imaging point A1 and the gamma angle rotation axis center point A4 are in the width direction of the treatment bed 03 A position Ix90, a second position Iy90 in the length direction of the treatment bed 03, and a third position Iz90 in the height direction of the treatment bed 03. That is, the fourth initial relative position can be expressed as: (Ix90, Iy90, Iz90). Correspondingly, the host computer 02 calculates the fourth relative position (Ix90, Iy90, Iz90) calculated based on the acquired gamma angle γ to be treated, the first length Ix, the second distance LI _YOZ and the second gamma angle γ2 Can meet:

Ix90 = Ix formula (1);

Iy90=LI _yoz ×cos(γ2-90°+γ) formula (2);

Iz90=LI _yoz ×sin(γ2-90°+γ) Formula (3).

With reference to the above formula (1), it can be seen that during the adjustment of the gamma angle γ, the position of the target point A3 only changes in the first plane YOZ, the coordinates of the target point A3 on the first axis X will not change, and That is, it is not necessary to consider the relative distance between the target point A3 and the imaging point A1 on the first axis X, so the first length Ix can be directly determined as the first position Ix90.

With reference to the above formula (2), it can be known that the product of the second distance LI _YOZ and the cosine value of the second angle α2 can be determined as the second position Iy90, where the second angle α2 can be the second gamma angle γ2 and 90 The angle obtained by adding the degrees and subtracting the gamma angle γ to be treated, that is, the second angle α2 can satisfy: α2=γ2+90°-γ.

It can be seen with reference to the above formula (3) that the product of the second distance LI _YOZ and the sine value of the second angle α2 can be determined as the third position Iz90.

Step S2: Acquire the fifth relative position of the target point and the imaging point when the gamma angle to be treated is 90 degrees.

In the embodiment of the present invention, since the target point A3 acquired by the host computer 02 is located in the image coordinate system, and the imaging point A1 is located in the device coordinate system, for convenience of calculation, the IGS system 01 may first position coordinates of the acquired target point A3 Convert to the device coordinate system so that the target point A3 and the imaging point A1 are in the same coordinate system. Referring to FIG. 1, the device coordinate system may be a first axis X extending along the width direction of the treatment bed 03, a second axis Y extending along the length direction of the treatment bed 03, and a third axis extending along the height direction of the treatment bed 03 A three-dimensional coordinate system composed of axis Z.

Correspondingly, the fifth relative position may include: the distance TIx of the target point A3 and the imaging point A1 in the width direction of the treatment bed 03, the distance TIy in the length direction of the treatment bed 03, and the height of the treatment bed 03 The relative distance TIz in the direction. That is, the fifth relative position of the target point A3 and the imaging point A1 can be expressed as: (TIx, TIy, TIz).

For example, suppose that the host computer 02 converts the acquired position of the target point A3 to the device coordinate system. The coordinates of the target point A3 are: (Xb, Yb, Zb), and the coordinates of the acquired imaging point A1 in the device coordinate system are : (Xi, Yi, Zi). Then, the fifth relative position (TIx, TIy, TIz) of the determined target point A3 and the imaging point A1 may satisfy: TIx=Xb-Xi, TIy=Yb-Yi, TIz=Zb-Zi.

Step S3: Determine the sum of the fourth relative position and the fifth relative position as the target relative position.

In the embodiment of the present invention, the host computer 02 calculates the first target relative distance Tx90 in the target relative position according to the fourth relative position and the fifth relative position, which can be: Tx90=Ix90+TIx; the second target relative distance Ty90 is : Ty90=Iy90+TIy; the third target relative distance Tz90 is: Tz90=Iz90+TIz.

Step 4082: According to the relative distance between the second target and the third target, determine the first distance between the target point and the center point of the rotation axis of the gamma angle in the first plane when the gamma angle to be treated is 90 degrees.

In the same way as the above step x10, in the process of adjusting the gamma angle, the position of the target point A3 only changes in the first plane YOZ, the coordinate of the target point A3 on the first axis X will not change, so it is the upper position After calculating the relative position of the target (Tx90, Ty90, Tz90), the machine 02 can first calculate the target point A3 and the center point A4 of the rotation axis of the gamma angle according to the second target relative distance Ty90 and the third target relative distance Tz90. The first distance LT _yoz in the plane YOZ, the first distance LTyoz can satisfy:

Step 4083: Determine the first gamma angle according to the second target relative distance and the third target relative distance.

The host computer 02 determines the first gamma angle γ1 according to the second target relative distance Ty90 and the third target relative distance Tz90: γ1=arctan(Tz90/Ty90), that is, the first gamma angle γ1 may be the third The arc tangent of the ratio of the target relative distance Tz90 to the second target relative distance Ty90.

Step 4084: Calculate the third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated and the first distance.

In the embodiment of the present invention, the third relative position may also include: under the gamma angle γ to be treated, the first relative position of the target point A3 and the center point A4 of the rotation axis of the gamma angle in the width direction of the treatment bed 03 The distance Tx, the second relative distance Ty in the length direction of the treatment bed 03, and the third relative distance Tz in the height direction of the treatment bed 03. That is, the third relative position can be expressed as: (Tx, Ty, Tz). Correspondingly, the host computer 02 calculates the calculated third relative position (TIxg, TIyg, T1) based on the acquired first distance LT _yoz , first gamma angle γ1, gamma angle γ to be treated and the first target relative distance Tx90. TIzg) can satisfy:

Tx = Tx90 formula (4);

Ty = LT _yoz × cos(γ1-90°+γ) formula (5);

Tz=LT _yoz ×sin(γ1-90°+γ) Formula (6).

With reference to the above formula (4), it can be seen that, during the adjustment of the gamma angle γ, the position of the target point A3 only changes in the first plane YOZ, the coordinates of the target point A3 on the first axis X will not change, and That is, it is not necessary to consider the relative distance between the target point A3 and the imaging point A1 on the first axis X, so the first target relative distance Tx90 can be directly determined as the first relative distance Tx.

With reference to the above formula (5), it can be known that the product of the first distance LT _yoz and the cosine value of the first angle α1 can be determined as the second relative distance Ty, where the first angle α1 can be the first gamma angle γ1 and The angle obtained by adding 90 degrees and subtracting the gamma angle γ to be treated, that is, the first angle α1 can satisfy: α1=γ1+90°-γ.

It can be seen with reference to the above formula (6) that the product of the first distance LT _yoz and the sine value of the first angle α1 can be determined as the third relative distance Tz.

Step 409: According to the first coordinate, the first relative position, the second relative position, and the third relative position, calculate the second coordinate of the treatment bed when the target point coincides with the isocenter of the device under the gamma angle to be treated.

In the embodiment of the present invention, the host computer 02 may add the first coordinate and the first relative position and then subtract the third relative position, and then add the second relative position to obtain the gamma angle γ to be treated When the target point A3 coincides with the isocenter A2 of the device, the second coordinate of the treatment bed 03. The second coordinate may also include: a first-dimensional coordinate Xt extending in the width direction of the treatment bed 03, a second-dimensional coordinate Yt extending in the length direction of the treatment bed 03, and a third three-dimensional coordinate extending in the width direction of the treatment bed 03 Zt. That is, the second coordinate can be expressed as: (Xt, Yt, Zt), and the second coordinate (Xt, Yt, Zt) can satisfy:

Xt=X1+Xiso-Tx+Ix formula (7);

Yt=Y1+Yiso-Ty+Iy formula (8);

Zt=Z1+Ziso-Tz+Iz formula (9).

With reference to the above formula (7), it can be seen that the first coordinate X1 in the first coordinate is added to the first distance Xiso, then subtracted from the first relative distance Tx, and then added to the first length Ix to obtain The first dimension Xt.

With reference to the above formula (8), it can be seen that the second dimensional coordinate Y1 in the first coordinate is added to the second distance Yiso, then subtracted from the second relative distance Ty, and then added to the second length Iy to obtain The second coordinate Yt.

With reference to the above formula (9), it can be seen that the third coordinate Z1 in the first coordinates is added to the third distance Ziso, then subtracted from the third relative distance Tz, and then added to the third length Iz to obtain the first Three-dimensional coordinates Yt.

Step 410: Adjust the position of the treatment bed according to the second coordinates.

In the embodiment of the present invention, the host computer 02 can accurately adjust the position of the treatment bed 03 according to the calculated second coordinates (Xt, Yt, Zt). The alignment accuracy of the target point A3 and the equipment isocenter A2 under the gamma angle to be treated is improved, thereby further improving the accuracy of radiotherapy.

Optionally, the order of the steps of the positioning method provided in the embodiments of the present invention may be adjusted appropriately, and the steps may also be increased or decreased according to the situation. For example, the above steps 401 to 405 can be performed after the above step 408, that is, the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated can be obtained first, and then obtain The first coordinate of the treatment bed. Anyone who is familiar with the technical field can easily think of a change method within the technical scope disclosed by the present invention, which should be covered within the protection scope of the present invention, and thus will not be repeated here.

9 is a block diagram of a positioning device provided by an embodiment of the present invention. This device can be applied to the host computer 02 shown in FIG. 1, or, referring to the above description, it can be known that the positioning device can also be applied to the IGS system 01 or the treatment bed 03 shown in FIG. 1. Without limitation, the following embodiments take the positioning device applied to the host computer 02 as an example for description. As shown in FIG. 9, the device may include:

The first obtaining module 501 is used to obtain the gamma angle to be treated.

The second acquisition module 502 is used to acquire the first coordinates of the treatment bed. The first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS.

The third acquisition module 503 is used to acquire the first relative position of the imaging point and the isocenter of the device.

The fourth acquisition module 504 is used to acquire the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, the center point of the rotation axis of the gamma angle is the gamma angle of the gamma angle adjustment device for adjusting the gamma angle The center point of the axis of rotation.

The fifth acquisition module 505 is used to acquire the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated.

The calculation module 506 is used to calculate the first position of the treatment bed when the target point coincides with the isocenter of the device under the gamma angle to be treated according to the first coordinate, the first relative position, the second relative position and the third relative position Two coordinates.

The first adjustment module 507 is used to adjust the position of the treatment bed according to the second coordinate.

In summary, the embodiments of the present invention provide a positioning device. The calculation module in the device may be based on the first coordinate of the treatment bed acquired by the second acquisition module when the preset filming point coincides with the imaging point, and the imaging point acquired by the third acquisition module is first relative to the isocenter of the device Position, the second relative position of the imaging point acquired by the fourth acquisition module and the center point of the rotation axis of the gamma angle, and the target point and the gamma angle acquired by the fifth acquisition module under the gamma angle to be treated The third relative position of the center point of the rotation axis calculates the second coordinate of the treatment bed when the target point coincides with the isocenter of the device at the gamma angle to be treated. The first adjustment module can adjust the position. Therefore, when the gamma angle is adjusted during the radiotherapy process, the second coordinate of the treatment bed can be calculated accurately when the target point coincides with the isocenter of the device under the adjusted gamma angle. Improve the alignment accuracy of the target point and the isocenter of the device at different gamma angles, which can improve the accuracy of radiotherapy.

10 is a block diagram of another positioning device provided by an embodiment of the present invention. This device can be applied to the host computer 02 shown in FIG. 1, or, referring to the above description, it can be known that the positioning device can also be applied to the IGS system 01 or the treatment bed 03 shown in FIG. 1. Without limitation, the following embodiments take the positioning device applied to the host computer 02 as an example for description. As shown in FIG. 10, the device may include:

The sixth acquisition module 508 is used to acquire a reconstructed image of the gamma angle to be treated before acquiring the first coordinates of the treatment bed, the reconstructed image being an image reconstructed according to the electronic image of the affected part acquired in advance.

The seventh acquisition module 509 is used to acquire the IGS image of the affected part under the gamma angle to be treated, and the IGS image is an image generated by the image guidance system.

The second adjustment module 510 is used to perform image registration of the reconstructed image and the IGS image by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.

Optionally, the fourth acquiring module 504 may be used to: when the treatment bed is at the initial position, acquire the initial relative position of the imaging point and the center point of the rotation axis of the gamma angle, and compare the difference between the initial relative position and the first coordinate The value is determined as the second relative position.

FIG. 11 is a block diagram of a fifth obtaining module 505 provided by an embodiment of the present invention. As shown in FIG. 11, the fifth obtaining module 505 may include:

The obtaining submodule 5051 is used to obtain the target relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees. The relative position of the target includes: the relative distance between the target point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, the relative distance of the second target in the length direction of the treatment bed, and the height in the treatment bed The relative distance of the third target in the direction.

The first determining submodule 5052 is used to determine that the target point and the center point of the rotation axis of the gamma angle are in the first plane when the gamma angle to be treated is 90 degrees according to the relative distance between the second target and the third target The first distance. The first plane is a plane where a first axis extending along the length direction of the treatment bed and a second axis extending along the height direction of the treatment bed are located.

The second determination submodule 5053 is configured to determine the first gamma angle according to the second target relative distance and the third target relative distance.

The calculation submodule 5054 is configured to calculate a third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated, and the first distance.

Optionally, the third relative position may include: under the gamma angle to be treated, the first relative distance between the target point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, in the length direction of the treatment bed The second relative distance on the top, and the third relative distance in the height direction of the treatment bed.

Optionally, the calculation submodule 5054 may be used for:

The first target relative distance is determined as the first relative distance.

The product of the first distance and the cosine value of the first angle is determined as the second relative distance. The first angle is an angle obtained by adding the first gamma angle to 90 degrees and then subtracting the gamma angle to be treated.

Optionally, the acquisition submodule 5051 may be used for:

When the gamma angle to be treated is 90 degrees, the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle is obtained.

When the gamma angle to be treated is 90 degrees, the fifth relative position of the target point and the imaging point is obtained.

Optionally, the second relative position may include: a first length of the imaging point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, a second length in the length direction of the treatment bed, and a treatment bed The third length in the height direction.

Correspondingly, obtaining the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle by the obtaining submodule 5051 may include:

According to the second length and the third length, the second distance between the imaging point and the center point of the rotation axis of the gamma angle in the first plane under the gamma angle to be treated is calculated.

According to the second length and the third length, the second gamma angle is determined.

Based on the first length, the second gamma angle, the gamma angle to be treated, and the second distance, the fourth relative position is calculated.

Optionally, the fourth relative position may include: when the gamma angle to be treated is 90 degrees, the first position of the imaging point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, and the position of the treatment bed The second position in the length direction and the third position in the height direction of the treatment bed.

Correspondingly, the obtaining submodule 5051 calculating the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance may include:

The first length is determined as the first position.

The product of the second distance and the cosine value of the second angle is determined as the second position. The second angle is an angle obtained by adding the second gamma angle to 90 degrees and then subtracting the gamma angle to be treated.

Optionally, the calculation module 506 may be used to add the first coordinate and the first relative position and subtract the third relative position, and then add the second relative position to obtain the second coordinate of the treatment bed.

In summary, the embodiments of the present invention provide a positioning device. The calculation module in the device may be based on the first coordinates of the treatment bed acquired by the second acquisition module when the preset filming point coincides with the imaging point, and the imaging point acquired by the third acquisition module is first relative to the isocenter of the device Position, the second relative position of the imaging point acquired by the fourth acquisition module and the center point of the rotation axis of the gamma angle, and the target point and the gamma angle acquired by the fifth acquisition module under the gamma angle to be treated The third relative position of the center point of the rotation axis calculates the second coordinate of the treatment bed when the target point coincides with the isocenter of the device at the gamma angle to be treated. The first adjustment module can adjust the position. Therefore, when the gamma angle is adjusted during the radiotherapy process, the second coordinate of the treatment bed can be calculated accurately when the target point coincides with the isocenter of the device under the adjusted gamma angle. Improve the alignment accuracy of the target point and the isocenter of the device at different gamma angles, which can improve the accuracy of radiotherapy.

Regarding the positioning device in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be described in detail here.

An embodiment of the present invention provides a positioning device. The positioning device may include: a processor and a memory, where instructions are stored in the memory, and the instructions may be loaded and executed by the processor to implement the positioning method as shown in any of FIG. 3, FIG. 4, and FIG. 6.

In addition, an embodiment of the present invention provides a storage medium in which instructions are stored. When the storage medium runs on a processing component, the processing component can be executed as shown in any of FIG. 3, FIG. 4, and FIG. 6. Method of positioning.

An embodiment of the present invention also provides a radiation therapy system. The radiation therapy system may include: a positioning device as shown in any one of FIGS. 9 and 10.

Those skilled in the art can clearly understand that, for the convenience and conciseness of the description, the specific working processes of the devices and modules described above can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection of the present invention Within range.

Claims

A positioning method, characterized in that the method includes:

Obtain the gamma angle to be treated;

Acquiring the first coordinates of the treatment bed, where the first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS;

Acquiring the first relative position of the imaging point and the isocenter of the device;

Acquiring the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, the center point of the rotation axis of the gamma angle being the center point of the rotation axis of the gamma angle of the gamma angle adjustment device for adjusting the gamma angle ;

Acquiring the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated;

According to the first coordinate, the first relative position, the second relative position and the third relative position, calculate the isocenter of the target and the device under the gamma angle to be treated When the points coincide, the second coordinate of the treatment bed;

The position of the treatment bed is adjusted according to the second coordinate.
The method according to claim 1, wherein before the acquiring the first coordinates of the treatment bed, the method further comprises:

Acquiring a reconstructed image of the gamma angle to be treated, the reconstructed image being an image reconstructed according to an electronic image of the affected part acquired in advance;

Acquiring an IGS image of the affected part under the gamma angle to be treated, the IGS image being an image generated by the image guidance system;

The image registration of the reconstructed image and the IGS image is performed by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.
The method according to claim 1, wherein the acquiring the second relative position of the imaging point and the center point of the rotation axis of the gamma angle includes:

Acquiring the initial relative position of the imaging point and the center point of the rotation axis of the gamma angle when the treatment bed is at the initial position;

The difference between the initial relative position and the first coordinate is determined as the second relative position.
The method according to claim 1, wherein the acquiring the third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated includes:

Acquiring the target relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees, the target relative position includes: the target point and the gamma The first target relative distance in the width direction of the treatment bed, the second target relative distance in the length direction of the treatment bed, and the third target height in the height direction of the treatment bed Relative target distance

According to the relative distance of the second target and the relative distance of the third target, it is determined that when the gamma angle to be treated is 90 degrees, the center point of the target point and the rotation axis of the gamma angle is in the first plane Within the first distance, the first plane is the plane where the first axis extends along the length of the treatment bed and the second axis extends along the height of the treatment bed;

Determine the first gamma angle according to the relative distance of the second target and the relative distance of the third target;

The third relative position is calculated according to the first target relative distance, the first gamma angle, the gamma angle to be treated, and the first distance.
The method according to claim 4, wherein the third relative position comprises: under the gamma angle to be treated, the target point and the center point of the rotation axis of the gamma angle are at the treatment A first relative distance in the width direction of the bed, a second relative distance in the length direction of the treatment bed, and a third relative distance in the height direction of the treatment bed;

The calculating the third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated and the first distance includes:

Determining the first target relative distance as the first relative distance;

The product of the first distance and the cosine value of the first angle is determined as the second relative distance, and the first angle is to add the first gamma angle to 90 degrees, and then to the treatment The angle obtained by subtracting the gamma angle of

The product of the first distance and the sine value of the first angle is determined as the third relative distance.
The method according to claim 4, wherein the acquiring the relative position of the target point and the center point of the rotation axis center point of the gamma angle when the gamma angle to be treated is 90 degrees includes: :

When the gamma angle to be treated is 90 degrees, obtain a fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle;

When the gamma angle to be treated is 90 degrees, acquiring a fifth relative position of the target point and the imaging point;

The sum of the fourth relative position and the fifth relative position is determined as the target relative position.
The method according to claim 6, wherein the second relative position comprises: a first length of the imaging point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, at A second length in the length direction of the treatment bed, and a third length in the height direction of the treatment bed;

The acquiring the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees includes:

Calculating the second distance between the imaging point and the center point of the rotation axis of the gamma angle in the first plane under the gamma angle to be treated according to the second length and the third length ;

Determine the second gamma angle according to the second length and the third length;

The fourth relative position is calculated according to the first length, the second gamma angle, the gamma angle to be treated, and the second distance.
The method according to claim 7, wherein the fourth relative position comprises: when the gamma angle to be treated is 90 degrees, the imaging point and the center point of the gamma angle rotation axis are at A first position in the width direction of the treatment bed, a second position in the length direction of the treatment bed, and a third position in the height direction of the treatment bed;

The calculating the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance includes:

Determining the first length as the first position;

The product of the second distance and the cosine value of the second angle is determined as the second position, the second angle is the sum of the second gamma angle and 90 degrees, and then combined with the to-be-treated The angle obtained by subtracting the gamma angle;

The product of the second distance and the sine value of the second angle is determined as the third position.
The method according to any one of claims 1 to 7, wherein the calculation is based on the first coordinates, the first relative position, the second relative position, and the third relative position. Under the gamma angle to be treated, when the target point coincides with the isocenter of the device, the second coordinate of the treatment bed includes:

Adding the first coordinate and the first relative position to subtract the third relative position, and then adding the second relative position to obtain the second coordinate of the treatment bed.
A positioning device, characterized in that the device comprises:

The first acquisition module is used to acquire the gamma angle to be treated;

The second acquisition module is used to acquire the first coordinates of the treatment bed, where the first coordinates are the coordinates of the treatment bed when the preset filming point coincides with the imaging point of the image guidance system IGS;

A third acquisition module, configured to acquire the first relative position of the imaging point and the isocenter of the device;

A fourth obtaining module, configured to obtain the second relative position of the imaging point and the center point of the rotation axis of the gamma angle, the center point of the rotation axis of the gamma angle is the gamma of the gamma angle adjusting device for adjusting the gamma angle The center point of the rotation axis of the Mayer;

A fifth acquisition module, configured to acquire a third relative position of the target point of the affected part and the center point of the rotation axis of the gamma angle under the gamma angle to be treated;

The calculation module is configured to calculate the target point and the target angle under the gamma angle to be treated according to the first coordinate, the first relative position, the second relative position and the third relative position When the isocenter of the device coincides, the second coordinate of the treatment bed;

The first adjustment module is used to adjust the position of the treatment bed according to the second coordinate.
The device of claim 10, wherein the device further comprises:

A sixth acquisition module, configured to acquire a reconstructed image of the gamma angle to be treated before acquiring the first coordinates of the treatment bed, the reconstructed image being an image reconstructed from an electronic image of the affected part acquired in advance;

A seventh acquisition module, configured to acquire an IGS image of the affected part under the gamma angle to be treated, the IGS image being an image generated by the image guidance system;

The second adjustment module is used to perform image registration of the reconstructed image and the IGS image by adjusting the position of the treatment bed, so that the preset filming point coincides with the imaging point.
The apparatus according to claim 10, wherein the fourth acquisition module is configured to:

Acquiring the initial relative position of the imaging point and the center point of the rotation axis of the gamma angle when the treatment bed is at the initial position;

The difference between the initial relative position and the first coordinate is determined as the second relative position.
The apparatus according to claim 10, wherein the fifth acquisition module comprises:

An acquisition sub-module for acquiring the relative position of the target point and the center point of the rotation axis of the gamma angle when the gamma angle to be treated is 90 degrees, the target relative position includes: the target The relative distance between the point and the first target in the width direction of the treatment bed of the center point of the rotation axis of the gamma angle, the relative distance of the second target in the length direction of the treatment bed, and the The relative distance of the third target in the height direction;

A first determining submodule, configured to determine the target point and the gamma angle when the gamma angle to be treated is 90 degrees according to the relative distance between the second target and the third target A first distance of the center point of the rotation axis in a first plane, where the first plane is a plane where a first axis extending along the length of the treatment bed and a second axis extending along the height of the treatment bed are located ;

A second determining submodule, configured to determine the first gamma angle according to the relative distance of the second target and the relative distance of the third target;

The calculation submodule is configured to calculate the third relative position according to the first target relative distance, the first gamma angle, the gamma angle to be treated, and the first distance.
The apparatus according to claim 13, wherein the third relative position includes: under the gamma angle to be treated, the target point and the center point of the rotation axis of the gamma angle are at the treatment A first relative distance in the width direction of the bed, a second relative distance in the length direction of the treatment bed, and a third relative distance in the height direction of the treatment bed;

The calculation submodule is used for:

Determining the first target relative distance as the first relative distance;

The product of the first distance and the cosine value of the first angle is determined as the second relative distance, and the first angle is to add the first gamma angle to 90 degrees, and then to the treatment The angle obtained by subtracting the gamma angle of

The product of the first distance and the sine value of the first angle is determined as the third relative distance.
The apparatus according to claim 13, wherein the acquisition submodule is configured to:

When the gamma angle to be treated is 90 degrees, obtain a fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle;

When the gamma angle to be treated is 90 degrees, obtain a fifth relative position of the target point and the imaging point;

The sum of the fourth relative position and the fifth relative position is determined as the target relative position.
The device according to claim 15, wherein the second relative position includes: a first length of the imaging point and the center point of the rotation axis of the gamma angle in the width direction of the treatment bed, at A second length in the length direction of the treatment bed, and a third length in the height direction of the treatment bed;

The acquiring submodule acquiring the fourth relative position of the imaging point and the center point of the rotation axis of the gamma angle includes:

Calculating the second distance between the imaging point and the center point of the rotation axis of the gamma angle in the first plane under the gamma angle to be treated according to the second length and the third length ;

Determine the second gamma angle according to the second length and the third length;

The fourth relative position is calculated according to the first length, the second gamma angle, the gamma angle to be treated, and the second distance.
The apparatus according to claim 16, wherein the fourth relative position includes: when the gamma angle to be treated is 90 degrees, the imaging point and the center point of the gamma angle rotation axis are at A first position in the width direction of the treatment bed, a second position in the length direction of the treatment bed, and a third position in the height direction of the treatment bed;

The obtaining submodule calculating the fourth relative position according to the first length, the second gamma angle, the gamma angle to be treated and the second distance includes:

Determining the first length as the first position;

The product of the second distance and the cosine value of the second angle is determined as the second position, the second angle is the sum of the second gamma angle and 90 degrees, and then combined with the to-be-treated The angle obtained by subtracting the gamma angle;

The product of the second distance and the sine value of the second angle is determined as the third position.
The device according to any one of claims 10 to 16, wherein the calculation module is configured to:

The first coordinate and the first relative position are added and then subtracted from the third relative position, and then added to the second relative position to obtain the second coordinate of the treatment bed.
A positioning device, characterized in that the device comprises:

A processor and a memory, wherein the memory stores instructions, and the instructions are loaded and executed by the processor to implement the positioning method according to any one of claims 1 to 9.
A storage medium characterized in that instructions are stored in the storage medium, and when the storage medium runs on a processing component, the processing component is caused to execute the positioning method according to any one of claims 1 to 9.
A radiation therapy system, characterized in that the radiation therapy system comprises: the positioning device according to any one of claims 10 to 18.