A method, apparatus, equipment and medium for detecting isocenter points

Abstract

A method, apparatus, device, and medium for isocenter point detection are disclosed, relating to the field of data processing technology. The method includes: with the gantry and radiator of a radiotherapy device both at initial angles, acquiring a first set of coordinates for multiple measurement points on the surfaces of the gantry and radiator; for each measurement point, performing the following: determining a second coordinate value of the measurement point after the radiator rotates by a target angle based on the first coordinate value of the measurement point through spatial coordinate transformation; determining a third coordinate value of the common intersection point after the gantry rotates by the target angle; determining a fourth coordinate value of the measurement point after rotation by superimposing the second and third coordinate values; generating a three-dimensional point cloud data set based on the fourth coordinate values ​​of multiple measurement points after rotation; and determining the center coordinates of the smallest envelope sphere as the dynamic isocenter point by calculating the smallest envelope sphere that encloses the three-dimensional point cloud data set. This provides a more comprehensive isocenter detection method, thereby increasing the reliability and safety of clinical treatment.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a method, apparatus, equipment and medium for detecting isocenter points. Background Technology

[0002] Radiotherapy equipment is a medical device that uses ionizing radiation to precisely kill tumor tissue. Its effectiveness relies on the high degree of spatial alignment between the radiation beam and the tumor target area. The isocenter, as the theoretical intersection of the gantry rotation axis, the radiation head rotation axis, and the treatment bed rotation axis, directly determines the effectiveness of the radiotherapy. Currently, modern precision radiotherapy technology requires the isocenter error to be controlled within ±1 mm. A large error in the isocenter can lead to deviations in the target area dose distribution, potentially causing damage to normal tissues or failure to control the tumor.

[0003] In related technologies, two methods are commonly used for isocenter detection. The first is the forward-pointing method: This method assesses isocenter deviation in a two-dimensional plane using the pointer trajectory. While simple to operate, this method only considers the two-dimensional deviation of a single rotating plane, neglecting the influence of axial displacement on the isocenter in three-dimensional space. The second is the standard sphere method: This method determines the isocenter by establishing a spatial coordinate system and measuring the position of the sphere's center. Although this method overcomes the two-dimensional limitation of the forward-pointing method, each measurement can only capture the static isocenter position under discrete gantry angles, failing to capture the dynamic trajectory during the continuous rotation of the radiotherapy equipment.

[0004] Therefore, determining a more comprehensive isocenter testing method to increase the reliability and safety of clinical treatment has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method, apparatus, device, and medium for isocenter detection, which can provide a more comprehensive isocenter detection method, thereby increasing the reliability and safety of clinical treatment.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] In a first aspect, this application discloses a method for detecting isocenter points, the method comprising:

[0008] With the gantry and radiation head of the radiotherapy equipment both at their initial angles, a first set of coordinates is acquired from multiple measurement points on the surface of the gantry and the surface of the radiation head of the radiotherapy equipment.

[0009] For each measurement point, the following steps are performed: Based on the first coordinate value of the measurement point, a second coordinate value of the measurement point is determined by spatial coordinate transformation after the radiator head rotates by the target angle; a third coordinate value of the common intersection point after the frame rotates by the target angle is determined, wherein the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator head; and a fourth coordinate value of the measurement point after rotation is determined by superimposing the second coordinate value and the third coordinate value.

[0010] A three-dimensional point cloud data set is generated based on the fourth coordinate value of the multiple measurement points after rotation.

[0011] By calculating the minimum envelope sphere that encloses the three-dimensional point cloud data set, the coordinates of the center of the minimum envelope sphere are determined to be the dynamic isocenter point.

[0012] Optionally, if the first coordinate value of the measurement point is (x1, y1, z1) and the target angle is θ, the second coordinate value of the measurement point is determined by spatial coordinate transformation as (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ).

[0013] Optionally, if the second coordinate value of the measurement point is (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ) and the third coordinate value of the common intersection point is (x2, y2, z2), then the fourth coordinate value of the measurement point after rotation is (x1cosθ + z1sinθ + x2, y1 + y2, -x1sinθ + z1cosθ + z2).

[0014] Optionally, the initial angle is the 0° rotation angle of the frame, at which point the radiating head is located directly above the frame. The target angle is selected at equal intervals according to the target step size and covers a range from 0° to 360°.

[0015] Secondly, this application discloses a detection device for isocenter points, the device comprising: a set acquisition module, a coordinate determination module, a set generation module, and a center determination module;

[0016] The acquisition module is used to acquire a first set of coordinates of multiple measurement points on the surface of the radiotherapy equipment frame and the surface of the radiotherapy equipment when both the frame and the radiation head are at their initial angles.

[0017] The coordinate determination module is configured to, for each measurement point, perform the following steps: based on the first coordinate value of the measurement point, determine the second coordinate value of the measurement point after the radiator rotates by the target angle through spatial coordinate transformation; determine the third coordinate value of the common intersection point after the frame rotates by the target angle, wherein the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator; and determine the fourth coordinate value of the measurement point after rotation by superimposing the second coordinate value and the third coordinate value.

[0018] The set generation module is used to generate a three-dimensional point cloud data set based on the fourth coordinate value of the multiple measurement points after rotation.

[0019] The center determination module is used to determine the center coordinates of the minimum envelope sphere as a dynamic isocenter point by calculating the minimum envelope sphere that encloses the three-dimensional point cloud data set.

[0020] Optionally, if the first coordinate value of the measurement point is (x1, y1, z1) and the target angle is θ, the second coordinate value of the measurement point is determined by spatial coordinate transformation as (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ).

[0021] Optionally, if the second coordinate value of the measurement point is (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ) and the third coordinate value of the common intersection point is (x2, y2, z2), then the fourth coordinate value of the measurement point after rotation is (x1cosθ + z1sinθ + x2, y1 + y2, -x1sinθ + z1cosθ + z2).

[0022] Optionally, the initial angle is the 0° rotation angle of the frame, at which point the radiating head is located directly above the frame. The target angle is selected at equal intervals according to the target step size and covers a range from 0° to 360°.

[0023] Thirdly, this application discloses an isocenter point detection device, the device comprising: a memory and a processor;

[0024] The memory is used to store programs;

[0025] The processor is configured to execute the program to implement the various steps of the isocenter detection method as described in the first aspect.

[0026] Fourthly, this application discloses a computer-readable medium having a computer program stored thereon, which, when executed by a processor, implements the various steps of the isocenter detection method as described in the first aspect.

[0027] Compared with the prior art, this application has the following beneficial effects:

[0028] This application discloses a method, apparatus, device, and medium for detecting isocenter points. The method includes: with the gantry and radiator of a radiotherapy device both at an initial angle, acquiring a first set of coordinates for multiple measurement points on the surface of the gantry and the surface of the radiator; for each measurement point, performing the following steps: determining a second coordinate value of the measurement point after the radiator rotates by a target angle based on the first coordinate value of the measurement point through spatial coordinate transformation; determining a third coordinate value of the common intersection point after the gantry rotates by a target angle, wherein the common intersection point is the intersection of the rotation axis of the gantry and the rotation axis of the radiator; determining a fourth coordinate value of the measurement point after rotation by superimposing the second and third coordinate values; generating a three-dimensional point cloud data set based on the fourth coordinate values ​​of multiple measurement points after rotation; and determining the center coordinates of the smallest envelope sphere of the envelope three-dimensional point cloud data set as the dynamic isocenter point by calculating the smallest envelope sphere. Therefore, the center point detection method provided in this application embodiment can fully consider the spatial distribution of all measurement points during the rotation of the radiation head, thereby improving the comprehensiveness and accuracy of isocenter point detection. This enables the radiotherapy equipment to precisely rotate and adjust around the isocenter point during treatment, ensuring that the radiation is always focused on the tumor site, reducing false radiation to surrounding normal tissues, and thus increasing the reliability and safety of clinical treatment. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram illustrating the principle of a forward pointer method.

[0031] Figure 2A This is a schematic diagram of a problem using the forward pointer method;

[0032] Figure 2B This is a schematic diagram of another problem using the forward pointer method;

[0033] Figure 3A A schematic diagram of a common intersection point;

[0034] Figure 3B This is a schematic diagram of the common intersection point of a forward pointer method;

[0035] Figure 3C A schematic diagram of the common intersection points of a standard ball method;

[0036] Figure 4A This is a schematic diagram of an isocentric envelope with a frame angle of 0 degrees and a radiating head angle of 0 degrees.

[0037] Figure 4B This is a schematic diagram of an isocentric envelope with a frame of 270 degrees and a radiating head of 0 degrees;

[0038] Figure 5 A flowchart illustrating a method for detecting isocenter points provided in this application embodiment;

[0039] Figure 6 A schematic diagram of a rack rotation and stacking method provided in an embodiment of this application;

[0040] Figure 7 A schematic diagram of an isocenter point detection device provided in an embodiment of this application;

[0041] Figure 8 This is a schematic diagram of a computer-readable medium provided in an embodiment of this application. Detailed Implementation

[0042] As described above, there are currently two common methods for detecting isocenters. The first method is the front pointer method, and the second method is the standard sphere method.

[0043] See Figure 1 The diagram illustrates the principle of the front pointer method. The specific operation flow of the front pointer method is as follows:

[0044] The first step is to rigidly fix the front pointer to the front end of the radiator head to ensure that the front pointer rotates synchronously with the radiator head. This ensures that the front pointer can accurately reflect the motion state of the radiator head during subsequent measurements.

[0045] The second step is to rotate the gantry to 180°, at which point the radiation head is perpendicular to the treatment bed. Then, by adjusting the position of the treatment bed, the tip of the front pointer is brought into point contact with the tip of reference pointer 1 (which is horizontally fixed to the treatment bed surface).

[0046] The third step is to rotate the radiator head 180°, observe the displacement range of the tip of the front pointer relative to the tip of the reference pointer 1, and adjust the position of the front pointer based on the displacement range until the displacement range converges to ±ε (ε is a preset threshold, such as 0.1mm).

[0047] The fourth step is to repeat the calibration process of the third step at the 90°, 0° and 270° positions of the frame to ensure that the displacement in the X / Z directions is minimized, thereby eliminating the influence of different gravity directions on the measurement results.

[0048] Fifth, take the average spatial coordinates of the tip of reference pointer 1 during multiple calibration processes as the isocenter point, and rotate the frame plane (e.g., Figure 1 The maximum displacement radius r1 of circle 1) and the rotation plane of the radiating head (such as circle 1) Figure 1 The root of the sum of the squares of the maximum displacement radius r2 of circle 2 is taken as the radius of the envelope sphere.

[0049] However, the front pointer method has the following three drawbacks:

[0050] First, the forward pointer method assumes that the displacement directions of the rack rotation plane and the radiator rotation plane are orthogonal (e.g., Figure 1 (As shown). For example, with the maximum displacement radius r1 of the frame rotation plane = 0.3 mm, the maximum displacement radius r2 of the radiator rotation plane = 0.4 mm, and the displacement directions of the frame rotation plane and the radiator rotation plane being orthogonal, the theoretical envelope sphere radius R = 0.5 mm. However, the measuring tool used in the front pointer method (usually a dial indicator) can only obtain the displacement amplitude and lacks directional guidance, making it impossible to detect the actual spatial angle between the two rotation planes. Because the actual spatial angle cannot be accurately determined, the front pointer method can only make an estimate. This estimation lacks accuracy; the estimated value may be too large or too small. If the estimated value is too large, it is equivalent to reserving a safety margin to a certain extent; but if the estimated value is too small, it will affect the actual result of the isocenter point. See [link to relevant documentation]. Figure 2A The figure illustrates a problem using the forward pointer method. If the forward pointer method, based on the assumed direction, is used to estimate the problem by simply adding the two maximum displacement radii, then R = 0.3 + 0.4 = 0.7 mm ≠ 0.5 mm, leading to a deviation in the results for the isocenter point.

[0051] Second, see Figure 2B The diagram illustrates another problem with the front pointer method. When the rotation plane of the frame and the rotation plane of the radiation head are not perfectly perpendicular due to installation errors, elastic deformation caused by the weight of the radiator, or other reasons, and instead have a certain angle between them, the radius of the envelope sphere will also change. For example... Figure 2B As shown, when the rotation plane of the frame and the rotation plane of the radiator are perpendicular, the diameter of the envelope sphere is 50. However, after a certain angle is formed, the diameter of the envelope sphere becomes 58.17, which leads to a deviation in the result of the isocenter point.

[0052] Third, the measurement data of the front pointer method is only based on the plane of rotation and cannot take into account data in a third direction in space. In practical applications, the axial runout changes caused by installation errors, bearing runout, etc., cannot be ignored, which makes the measurement results of the front pointer method incomplete.

[0053] Therefore, due to the aforementioned shortcomings of the anterior pointer method, which reduces the reliability and safety of clinical treatment, the standard sphere method was developed. The standard sphere method determines the isocenter by establishing a spatial coordinate system and measuring the position of the sphere's center. While this method overcomes the two-dimensional limitations of the anterior pointer method, each measurement can only capture the static isocenter position under discrete gantry angles, failing to capture the dynamic trajectory of the radiotherapy equipment during continuous rotation.

[0054] Furthermore, it's important to clarify that both the front pointer method and the standard sphere method rely on a core geometric feature: the gantry rotation axis and the radiator rotation axis share a common intersection point in three-dimensional space. This common intersection point refers to the point where the axes of the gantry rotation plane and the radiator rotation plane intersect. See also... Figure 3A This diagram illustrates a common intersection point. Figure 3A The two circles in the diagram represent the frame rotation plane and the radiator rotation plane, respectively. Each plane has an axis; the intersection of these two axes is the isocenter point, which is also the common intersection point. See also... Figure 3B The figure illustrates a common intersection point in the front pointer method. Because the front pointer method mandates that the gantry rotation plane and the radiator rotation plane be orthogonal (90° angle), a common intersection point exists, and the position of this intersection point is determined through two-dimensional plane calibration of the mechanical pointer. See also... Figure 3C The figure shows a schematic diagram of the common intersection point of a standard sphere method. Because the standard sphere method allows the rotation plane of the frame and the rotation plane of the radiator to be non-orthogonal (such as the actual 85°~95° angle), there is also a common intersection point, and the position of the intersection point is determined by reconstructing the spatial position of the two axes through three-dimensional imaging.

[0055] Existing methods rely on a single common intersection point of the rack rotation plane and the radiator rotation plane, which can only reflect the isocenter point at a specific angle (e.g., 0° for both the rack and the radiator) and cannot characterize the isocenter drift throughout the dynamic rotation process. Accurately determining the isocenter point of the radiator at various angles on the rack requires significant time and manpower. For example, see... Figure 4A This figure is a schematic diagram of an isocentric envelope with the frame at 0 degrees and the radiator at 0 degrees. Figure 4A shows the isocentric envelope when the frame and radiator are at 0 degrees. Ellipse 1 represents the minimum relative displacement data of the frame rotation, circle 1 represents the minimum relative displacement data of the radiator rotation, and the intersection of the two data points represents the center circle of the envelope sphere at this time, which is circle 2. See also Figure 4B The figure is a schematic diagram of an isocentric envelope with a frame of 270 degrees and a radiating head of 0 degrees. Figure 4BThe diagram shows the isocenter envelope when the frame is 270 degrees and the radiator is 0 degrees. Ellipse 1 remains unchanged, and the size of circle 1 remains unchanged, but the data intersection point changes to 270 degrees for the frame and 0 degrees for the radiator. At this time, the center circle of the envelope sphere becomes circle 3. The radii of circle 3 and circle 2 are not equal, indicating that the isocenter point is different at different angles, and accurate measurement requires a lot of resources.

[0056] In view of this, embodiments of this application provide a method, apparatus, device, and medium for isocenter detection. The isocenter detection method provided by embodiments of this application can fully consider the spatial distribution of all measurement points during the rotation of the radiation head, thereby improving the comprehensiveness and accuracy of isocenter detection. This enables the radiotherapy equipment to precisely rotate and adjust around the isocenter during treatment, ensuring that the radiation is always focused on the tumor site, reducing false radiation to surrounding normal tissues, and thus increasing the reliability and safety of clinical treatment.

[0057] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0058] See Figure 5 The figure is a flowchart of a method for detecting isocenter points provided in an embodiment of this application. The method includes:

[0059] S501: With the gantry and radiation head of the radiotherapy equipment both at their initial angles, acquire the first set of coordinates for multiple measurement points on the surface of the gantry and the surface of the radiation head of the radiotherapy equipment.

[0060] First, it is necessary to ensure that both the gantry and the radiation head of the radiotherapy equipment are at their initial angles. Typically, the initial angle is the gantry rotation angle of 0° (hereinafter referred to as the gantry 0° position), at which point the radiation head is directly above the gantry.

[0061] Understandably, using a standard sphere calibration tool, the intersection of the gantry rotation axis (Y-axis) and the radiation head rotation axis (Z-axis) is set as the origin (0,0,0) of the coordinate system, establishing a three-dimensional coordinate system: the Z-axis is the vertical direction, corresponding to the rotation axis direction of the radiation head when the gantry is at 0°; the Y-axis is the direction of the long axis of the treatment bed and the rotation axis direction of the gantry, corresponding to the rotation axis direction of the gantry; the X-axis is the horizontal direction.

[0062] In one specific implementation, to ensure the accuracy of the 0° position of the frame, calibration can be performed using a laser collimator or an electronic level. The calibration requirement is to ensure that the geometrical error between the 0° position of the frame and the 0° position of the radiator is ≤0.2mm, thereby reducing measurement errors and improving the accuracy of subsequent calculations.

[0063] Subsequently, with the gantry and radiator of the radiotherapy equipment at their initial angles, high-precision measuring equipment such as laser rangefinders, 3D coordinate measuring machines, and structured light scanners are used to collect coordinates at multiple measurement points on the surface of the gantry and radiator of the radiotherapy equipment, resulting in a first set of coordinates for these measurement points. This first set of coordinates is typically stored in a table, with each row corresponding to the 3D coordinates (x1, y1, z1) of a measurement point.

[0064] It should be noted that in practical applications, multiple measurement points can be evenly distributed across the surfaces of the rack and radiator, using methods such as mesh generation and curvature adaptive sampling, depending on the shape and size of the rack and radiator. Mesh generation involves dividing the rack and radiator surfaces into several regular small regions (such as rectangles or triangles) and selecting a representative measurement point within each region. Mesh generation is suitable for racks and radiators with regular shapes and is simple and easy to implement. Curvature adaptive sampling involves increasing the density of measurement points in areas with large curvature changes (such as spherical or elliptical surfaces) and decreasing the number of measurement points in areas with small curvature changes. Curvature adaptive sampling is suitable for irregularly shaped racks and radiators, enabling more efficient capture of the overall geometric features of the rack and radiator while reducing redundant data. By evenly distributing multiple measurement points across the rack and radiator surfaces, misjudgments of the overall spatial position of the rack and radiator can be avoided due to multiple measurement points being concentrated in localized areas. For example, if the measurement points are concentrated only at end A of the radiator, the calculated isocenter point may be biased towards end A, resulting in a large error.

[0065] S502: For each measurement point, perform the following: Based on the first coordinate value of the measurement point, determine the second coordinate value of the measurement point after the radiator rotates to the target angle through spatial coordinate transformation; determine the third coordinate value of the common intersection point after the frame rotates to the target angle, where the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator; determine the fourth coordinate value of the measurement point after rotation by superimposing the second and third coordinate values.

[0066] See Figure 6 The figure is a schematic diagram of a rack rotation superposition method provided in an embodiment of this application. First, based on the first coordinate value of the measurement point and combined with the rotation target angle of the radiator, the second coordinate value of the measurement point after the radiator rotates to the target angle is calculated using a three-dimensional spatial rotation matrix.

[0067] In one specific implementation, when the first coordinates of the measurement point are (x1, y1, z1) and the target angle is θ (e.g., 45°, 90°, 180°, etc.), the second coordinates of the measurement point can be derived based on the principle of spatial rotation matrix transformation, specifically (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ). Here, x1cosθ + z1sinθ represents the new x-coordinate after rotation, y1 remains unchanged because the rotation occurs in the xz plane, and -x1sinθ + z1cosθ represents the new z-coordinate after rotation. For example, when the first coordinates of measurement point A are (1, 2, 3) and the target angle θ is 90°, the second coordinates of measurement point A are (1×0 + 3×1, 2, -1×1 + 3×0) = (3, 2, -1). It should be noted that the target angle can be selected at equal intervals according to the target step size (such as 10°, 15°, etc.) and covers the range from 0° to 360°, thereby enabling a comprehensive analysis of the positional changes of the measurement point under different rotation angles. This application does not limit the specific target angle.

[0068] Subsequently, the third coordinate value of the common intersection point after the rack rotates to the target angle is determined. The common intersection point is the point where the rotation axis of the rack intersects with the rotation axis of the radiator. The position of the common intersection point in three-dimensional space changes under different rack rotation angles, therefore, its new coordinate value (i.e., the third coordinate value) needs to be calculated.

[0069] In one specific implementation, if the design drawings or specifications of the radiotherapy equipment provide the geometric relationship between the gantry and the radiator head, these parameters can be directly used to calculate the third coordinate value (x2, y2, z2). In another specific implementation, if the equations of the gantry rotation axis and the radiator head rotation axis, as well as their relative positional relationship, are known, the third coordinate value (x2, y2, z2) can be calculated by solving the system of equations. This application does not limit the method for determining the third coordinate value.

[0070] Finally, by superimposing the second and third coordinate values, the final position of the measurement point after rotation (i.e., the fourth coordinate value) is obtained. This step takes into account the effects of the radiator's own rotation and the frame rotation.

[0071] In one specific implementation, after the rack rotates by the target angle, the coordinates of the common intersection point in the rack coordinate system can be determined using data collected from the rack; this is the third coordinate value (x2, y2, z2). The third coordinate value (x2, y2, z2) represents the new position of the initial common intersection point in the rack coordinate system after the rack rotation. Given that the second coordinate value of the measurement point is (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ) and the third coordinate value of the common intersection point is (x2, y2, z2), the fourth coordinate value of the measurement point after rotation is (x1cosθ + z1sinθ + x2, y1 + y2, -x1sinθ + z1cosθ + z2). The fourth coordinate value of the measurement point after rotation is the superposition of the coordinates of the measurement point after the radiator head rotation (the second coordinate value) and the coordinates of the common intersection point in the rack coordinate system after the rack rotation (the third coordinate value). The significance of this superposition operation is to transform the rotational position of the measurement point in the radiator coordinate system to the frame coordinate system, thereby obtaining the accurate coordinates of the measurement point under the condition of overall equipment rotation. For example, when the second coordinate value of measurement point A is (3, 2, -1) and the third coordinate value of the common intersection point is (1, 1, 1), the fourth coordinate value of measurement point A after rotation is (3+1, 2+1, -1+1) = (4, 3, 0).

[0072] S503: Generate a set of three-dimensional point cloud data based on the fourth coordinate values ​​of multiple measurement points after rotation.

[0073] To comprehensively reflect the positional changes of measurement points on the radiator surface in three-dimensional space, it is necessary to integrate the fourth coordinate values ​​of all measurement points after rotation into a unified dataset, namely a three-dimensional point cloud dataset. A three-dimensional point cloud dataset is a data structure that represents the geometric characteristics of an object's surface in the form of discrete points. By generating a three-dimensional point cloud dataset, the spatial position and shape changes of the radiator during dynamic rotation can be intuitively reflected.

[0074] It should be noted that 3D point cloud datasets are typically stored in specific formats, such as comma-separated value (CSV) files or text files. This application does not limit the specific storage method.

[0075] S504: By calculating the minimum envelope sphere of the envelope 3D point cloud data set, the coordinates of the center of the minimum envelope sphere are determined as the dynamic isocenter point.

[0076] The minimum envelope sphere is the smallest sphere that can completely cover all points in a 3D point cloud dataset. "Complete coverage" means that the sphere's interior or surface contains every point in the 3D point cloud dataset; "minimum" requires that the sphere's radius be as small as possible while still satisfying the coverage condition. The coordinates of the minimum envelope sphere's center have significant geometric meaning, representing the geometric center of the 3D point cloud dataset. In radiotherapy equipment, these center coordinates are the dynamic isocenter point, reflecting the ideal position of the isocenter during continuous rotation of the radiotherapy equipment.

[0077] In one specific implementation, the minimum envelope sphere can be determined using methods such as genetic algorithms or simulated annealing. This application does not limit the specific method used to determine the minimum envelope sphere.

[0078] In summary, the embodiments of this application provide a method for detecting isocenters. The isocenter detection method provided by the embodiments of this application can fully consider the spatial distribution of all measurement points during the rotation of the radiation head, thereby improving the comprehensiveness and accuracy of isocenter detection. This enables the radiotherapy equipment to precisely rotate and adjust around the isocenter during treatment, ensuring that the radiation is always focused on the tumor site, reducing false radiation to surrounding normal tissues, and thus increasing the reliability and safety of clinical treatment.

[0079] See Figure 7 The figure is a schematic diagram of an isocenter point detection device provided in an embodiment of this application. The isocenter point detection device 700 includes: a set acquisition module 701, a coordinate determination module 702, a set generation module 703, and a center determination module 704.

[0080] The data acquisition module 701 is used to acquire the first set of coordinates of multiple measurement points on the surface of the radiotherapy equipment frame and the surface of the radiotherapy equipment when both the frame and the radiation head are at the initial angle.

[0081] The coordinate determination module 702 is used to perform the following for each measurement point: based on the first coordinate value of the measurement point, determine the second coordinate value of the measurement point after the radiator rotates by the target angle through spatial coordinate transformation; determine the third coordinate value of the common intersection point after the frame rotates by the target angle, where the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator; and determine the fourth coordinate value of the measurement point after rotation by superimposing the second and third coordinate values.

[0082] The set generation module 703 is used to generate a three-dimensional point cloud data set based on the fourth coordinate values ​​of multiple measurement points after rotation.

[0083] The center determination module 704 is used to determine the center coordinates of the minimum envelope sphere as the dynamic isocenter point by calculating the minimum envelope sphere of the envelope 3D point cloud data set.

[0084] In one specific implementation, given that the first coordinates of the measurement point are (x1, y1, z1) and the target angle is θ, the second coordinates of the measurement point are determined by spatial coordinate transformation as (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ).

[0085] In one specific implementation, with the second coordinate value of the measurement point being (x1cosθ+z1sinθ, y1, -x1sinθ+z1cosθ) and the third coordinate value of the common intersection point being (x2, y2, z2), the fourth coordinate value of the measurement point after rotation is (x1cosθ+z1sinθ+x2, y1+y2, -x1sinθ+z1cosθ+z2).

[0086] In one specific implementation, the initial angle is the 0° rotation angle of the rack. At this time, the radiator head is located directly above the rack. The target angle is selected at equal intervals according to the target step size and covers the range from 0° to 360°.

[0087] In summary, the embodiments of this application provide an isocenter detection device. The isocenter detection device provided by the embodiments of this application can fully consider the spatial distribution of all measurement points during the rotation of the radiation head, thereby improving the comprehensiveness and accuracy of isocenter detection. This enables the radiotherapy equipment to precisely rotate and adjust around the isocenter during treatment, ensuring that the radiation is always focused on the tumor site, reducing false radiation to surrounding normal tissues, and thus increasing the reliability and safety of clinical treatment.

[0088] This application also provides a corresponding isocenter detection device and a computer-readable medium for implementing the isocenter detection method provided in this application.

[0089] The isocenter detection device includes a memory and a processor. The memory is used to store instructions or code, and the processor is used to execute the instructions or code so that the device performs an isocenter detection method according to any embodiment of this application.

[0090] See Figure 8 This figure is a schematic diagram of a computer-readable medium provided in an embodiment of this application. The computer-readable medium 800 stores a computer program 811, which, when executed by a processor, implements the above-described... Figure 5 The steps of the method for detecting isocenter points.

[0091] It should be noted that, in the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0092] It should be noted that the machine-readable medium described above in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0093] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0094] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

[0095] While several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of this application. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0096] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for detecting isocenter points, characterized in that, The method includes: With the gantry and radiation head of the radiotherapy equipment both at their initial angles, a first set of coordinates is acquired from multiple measurement points on the surface of the gantry and the surface of the radiation head of the radiotherapy equipment. For each measurement point, the following steps are performed: Based on the first coordinate value of the measurement point, a second coordinate value of the measurement point is determined by spatial coordinate transformation after the radiator head rotates by the target angle; a third coordinate value of the common intersection point after the frame rotates by the target angle is determined, wherein the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator head; and a fourth coordinate value of the measurement point after rotation is determined by superimposing the second coordinate value and the third coordinate value. A three-dimensional point cloud data set is generated based on the fourth coordinate value of the multiple measurement points after rotation. By calculating the minimum envelope sphere that encloses the three-dimensional point cloud data set, the coordinates of the center of the minimum envelope sphere are determined to be the dynamic isocenter point.

2. The method according to claim 1, characterized in that, Given that the first coordinate value of the measurement point is (x1, y1, z1) and the target angle is θ, the second coordinate value of the measurement point is determined by spatial coordinate transformation as (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ).

3. The method according to claim 2, characterized in that, Given that the second coordinate value of the measurement point is (x1cosθ+z1sinθ,y1,-x1sinθ+z1cosθ) and the third coordinate value of the common intersection point is (x2,y2,z2), the fourth coordinate value of the measurement point after rotation is (x1cosθ+z1sinθ+x2,y1+y2,-x1sinθ+z1cosθ+z2).

4. The method according to claim 1, characterized in that, The initial angle is the 0° rotation angle of the frame. At this time, the radiating head is located directly above the frame. The target angle is selected at equal intervals according to the target step size and covers a range from 0° to 360°.

5. A device for detecting isocenter points, characterized in that, The device includes: a set acquisition module, a coordinate determination module, a set generation module, and a center determination module; The acquisition module is used to acquire a first set of coordinates of multiple measurement points on the surface of the radiotherapy equipment frame and the surface of the radiotherapy equipment when both the frame and the radiation head are at their initial angles. The coordinate determination module is configured to, for each measurement point, perform the following steps: based on the first coordinate value of the measurement point, determine the second coordinate value of the measurement point after the radiator rotates by the target angle through spatial coordinate transformation; determine the third coordinate value of the common intersection point after the frame rotates by the target angle, wherein the common intersection point is the intersection point of the rotation axis of the frame and the rotation axis of the radiator; and determine the fourth coordinate value of the measurement point after rotation by superimposing the second coordinate value and the third coordinate value. The set generation module is used to generate a three-dimensional point cloud data set based on the fourth coordinate value of the multiple measurement points after rotation. The center determination module is used to determine the center coordinates of the minimum envelope sphere as a dynamic isocenter point by calculating the minimum envelope sphere that encloses the three-dimensional point cloud data set.

6. The apparatus according to claim 5, characterized in that, Given that the first coordinate value of the measurement point is (x1, y1, z1) and the target angle is θ, the second coordinate value of the measurement point is determined by spatial coordinate transformation as (x1cosθ + z1sinθ, y1, -x1sinθ + z1cosθ).

7. The apparatus according to claim 6, characterized in that, Given that the second coordinate value of the measurement point is (x1cosθ+z1sinθ,y1,-x1sinθ+z1cosθ) and the third coordinate value of the common intersection point is (x2,y2,z2), the fourth coordinate value of the measurement point after rotation is (x1cosθ+z1sinθ+x2,y1+y2,-x1sinθ+z1cosθ+z2).

8. The apparatus according to claim 5, characterized in that, The initial angle is the 0° rotation angle of the frame. At this time, the radiating head is located directly above the frame. The target angle is selected at equal intervals according to the target step size and covers a range from 0° to 360°.

9. A detection device for isocenter points, characterized in that, The device includes: a memory and a processor; The memory is used to store programs; The processor is configured to execute the program to implement each step of the isocenter point detection method as described in any one of claims 1 to 4.

10. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements each step of the isocenter point detection method as described in any one of claims 1 to 4.

Images