Manufacturing method and device of radiotherapy headrest

Abstract

The present invention relates to a method and device for manufacturing a radiotherapy headrest, comprising obtaining an actual contour model of a patient's head in a first coordinate system; reconstructing the actual contour model into a first contour model based on treatment requirements as a first constraint; segmenting the first contour model into multiple layers of processing sub-regions according to a preset direction; orthographically projecting the outer contours of the first contour model onto corresponding processing sub-regions one by one to form a processing path; fixing a headrest blank in a second coordinate system, and processing the headrest blank in the second coordinate system using a hot melt head according to the processing path to obtain a radiotherapy headrest that is consistent with the outer contour of the first contour model. The method and device for manufacturing a radiotherapy headrest provided in this application can customize a radiotherapy headrest based on differences in patient head shape.

Description

Technical Field

[0001] The present invention belongs to the technical field of radiotherapy product manufacturing, and in particular, relates to a method and device for manufacturing a radiotherapy headrest. Background Art

[0002] Radiation therapy is one of the three main treatments for malignant tumors. Approximately 60% to 70% of cancer patients require radiation therapy. Like surgery, radiation therapy is a localized treatment approach, and 90% of tumor cure rates are attributed to local treatment. Failure of local control can lead to local tumor recurrence and distant metastasis. The fundamental goal of radiation therapy is to maximize the radiation dose delivered to the lesion (target area) to kill tumor cells while sparing or minimizing unnecessary radiation exposure to surrounding normal tissues and critical organs.

[0003] Therefore, patients need to be immobilized during radiotherapy to concentrate the radiation dose on the lesion, improve its effectiveness, and minimize the impact on other critical organs. However, if the tumor is located on the head, body shape differences, such as a hunchback or the tumor is located on the back of the head, can make it difficult to maintain head immobilization during radiotherapy. Existing radiotherapy headrests are all standardized, resulting in poor radiotherapy effectiveness. Summary of the Invention

[0004] To solve the above technical problems, the purpose of the present invention is to provide a method and device for manufacturing a radiotherapy headrest, which can be customized according to the differences in patient head shapes.

[0005] The technical solutions of the present invention are as follows:

[0006] A method for manufacturing a radiotherapy headrest, the method comprising: obtaining an actual contour model of a patient's head in a first coordinate system; reconstructing the actual contour model into a first contour model based on treatment requirements as a first constraint; segmenting the first contour model into multiple layers of processing sub-areas according to a preset direction; orthographically projecting the outer contours of the first contour model onto corresponding processing sub-areas one by one to form a processing path; fixing a headrest blank in a second coordinate system, and processing the headrest blank in the second coordinate system using a hot melt head according to the processing path to obtain a radiotherapy headrest consistent with the outer contour of the first contour model.

[0007] Preferably, obtaining the actual contour model of the patient's head in the first coordinate system includes: using different types of wavelength signals to perform tomographic scanning of the patient's head; receiving the reflected signal reflected back by the patient's head in response to the wavelength signal; the scanning point information includes the vertical distance corresponding to the scanning point relative to the X-axis, Y-axis and Z-axis in the first coordinate system; determining the first spatial coordinate point (X, Y, Z) corresponding to each scanning point based on each scanning point information, forming a first point set corresponding to the first spatial coordinate point (X, Y, Z), and then forming the actual contour model from the first point set.

[0008] Preferably, the reconstructing the actual contour model into the first contour model with the treatment requirement as the first constraint condition includes: when the first constraint condition is that the height of the bed on which the radiotherapy headrest is placed is the first distance value Z1, adjusting the first spatial point (X, Y, Z), obtaining the second spatial coordinate point (X, Y, Z-Z1) corresponding to each scanning point, and forming a second point set corresponding to the second spatial coordinate point (X, Y, Z-Z1), and reconstructing the first contour model from the second point set.

[0009] Preferably, the first coordinate system is constructed with the patient's body width as the X-axis, the patient's height as the Y-axis, and the direction between the patient's back and chest as the Z-axis; the reconstruction of the actual contour model into the first contour model with the treatment needs as the first constraint condition also includes: when the first constraint condition is that the patient's head is tilted relative to the back at an angle β when using a headrest to achieve different types of waves and important organs of the patient's head, the YZ plane formed by the Y-axis and the Z-axis in the first coordinate system is rotated by an angle of β, and the second spatial coordinate point (X, Y, Z-Z1) is transformed into a third spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ-Z1), forming a third point set corresponding to the third spatial coordinate point, and the first contour model is reconstructed from the third point set.

[0010] Preferably, when the first constraint condition is to raise the headrest height h, the third spatial coordinate point is transformed to form a fourth spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ+h-Z1), and the fourth point set corresponding to the fourth spatial coordinate point is reconstructed into the first contour model by the fourth point set.

[0011] Preferably, when the first constraint is that the patient's tumor grows on one or both sides of the head and needs to be treated in the lateral position, the X-axis and Z-axis in the first coordinate system are simultaneously rotated 90° in the positive direction and / or 90° in the negative direction around the Y-axis; when the X-axis and the Z-axis are rotated 90° in the positive direction, the fourth spatial coordinate point is transformed into a fifth spatial point (-Ysinβ-Zcosβ, Ycosβ-Zsinβ, X+h-Z1); when the X-axis and the Z-axis are rotated 90° in the negative direction, the fourth spatial coordinate point is transformed into a sixth spatial point (Ysinβ+Zcosβ, Ycosβ-Zsinβ, -X+h-Z1); the fifth spatial point and / or the sixth spatial point form a corresponding fifth point set, and the first contour model is reconstructed from the fifth point set.

[0012] Preferably, the second coordinate system has the same orientation as the first coordinate system; at least two layers of processing sub-areas are selected, corresponding to non-overlapping processing paths, and a second sub-area is formed by each processing path, and the hot melt head is rotated around the Y-axis by a certain angle so that the axis of the hot melt head is always perpendicular to the second sub-area.

[0013] Preferably, the hot melt head rotates 90° in the forward direction and / or 90° in the reverse direction around the X-axis.

[0014] Preferably, after obtaining a headrest having an outer contour consistent with the first contour model, a first positioning hole is machined on the headrest, and the first positioning hole cooperates with a positioning pin for fixing the headrest on the bracket during radiotherapy of the patient.

[0015] A device for manufacturing a radiotherapy headrest, the device comprising: a first acquisition module for acquiring an actual contour model of a patient's head in a first coordinate system; a first construction module for reconstructing the actual contour model into a first contour model based on treatment requirements as a first constraint; a first formation module for segmenting the first contour model into multiple layers of processing sub-areas according to a preset direction, and orthographically projecting the first contour models into the processing sub-areas one by one to form a processing path; a first processing module for fixing a headrest blank in a second coordinate system, and a hot melt head for processing the headrest blank in the second coordinate system according to the processing path to obtain a headrest consistent with the outer contour of the first contour model.

[0016] The method and apparatus for manufacturing a radiotherapy headrest provided by the present invention obtain an actual contour model of the patient's head within a first coordinate system based on the patient's age and head shape. The actual contour model is then adjusted based on the patient's different treatment needs as a first constraint, such as comfort, avoiding critical head organs, and different head tumor locations. The resulting first contour model is then reconstructed to better meet the patient's radiotherapy needs. The first contour model is then sliced into multiple layers of processing sub-regions along a preset direction. Each layer of processing sub-regions is then processed to obtain a radiotherapy headrest that conforms to the outer contour of the first contour model. Specifically, the outer contour of the first contour model in each layer is orthographically projected onto the corresponding processing sub-region to form a processing path. A headrest blank is then fixed in a second coordinate system. A hot melt head gradually melts the headrest blank in the second coordinate system according to the processing path, ultimately resulting in a radiotherapy headrest that conforms to the outer contour of the first contour model. Therefore, the method and apparatus for manufacturing a radiotherapy headrest provided by the present invention can customize radiotherapy headrests based on patient head shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide an understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A flow chart of a method for manufacturing a radiotherapy headrest provided by the present invention;

[0019] Figure 2 This is a framework diagram of the device for manufacturing the radiotherapy headrest provided by the present invention.

[0020] Description of Reference Numerals

[0021] 10. First acquisition module; 20. First construction module; 30. First forming module; 40. First processing module. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0023] In the description of the present invention, it should be understood that the terms "upper" and "lower" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0024] Please Figure 1 As shown, the present invention provides a method for manufacturing a radiotherapy headrest, the method comprising:

[0025] S10, obtaining an actual contour model of the patient's head in the first coordinate system;

[0026] S20, reconstructing the actual contour model into a first contour model with treatment requirements as the first constraint;

[0027] S30, dividing the first contour model into multi-layer processing sub-areas according to a preset direction;

[0028] S40, orthographically projecting the outer contours of the first contour model onto corresponding processing sub-areas one by one to form a processing path;

[0029] S50: Fix the headrest blank in the second coordinate system, and process the headrest blank in the second coordinate system according to the processing path using a hot melt head to obtain a radiotherapy headrest that is consistent with the outer contour of the first contour model.

[0030] The method for manufacturing a radiotherapy headrest provided by the present invention obtains an actual contour model of the patient's head within a first coordinate system based on the patient's age and head shape. The actual contour model is then adjusted based on the patient's different treatment needs as a first constraint, such as comfort, avoiding critical head organs, and different head tumor locations. The resulting first contour model is then reconstructed to better meet the patient's radiotherapy needs. The first contour model is then segmented into multiple layers of processing sub-regions along a preset direction. After each layer of processing sub-regions is processed, a radiotherapy headrest with an outer contour consistent with the first contour model is obtained. Specifically, the outer contour of the first contour model in each layer is orthographically projected onto the corresponding processing sub-region to form a processing path. The headrest blank is then fixed in a second coordinate system. A hot melt head is used in the second coordinate system to gradually melt the headrest blank according to the processing path, ultimately obtaining a radiotherapy headrest with an outer contour consistent with the first contour model. Therefore, the method and apparatus for manufacturing a radiotherapy headrest provided by the present invention can customize radiotherapy headrests based on patient head shapes.

[0031] The first contour model is segmented along a preset direction, where the preset direction is the axis direction of the first coordinate system. During segmentation, one of the axis directions can be selected. This divides the three-dimensional first contour model into multiple planes, with processing sub-regions located on these planes. Each plane has an outer contour corresponding to a different size of the first contour model. These outer contours are projected onto the processing sub-regions one by one, forming a multi-layer processing path. The hot melt head then moves along the processing path layer by layer, melting the headrest blank, ultimately forming a radiotherapy headrest consistent with the outer contour of the first contour model. If necessary, the temperature and speed of the hot melt head are adjusted to achieve a smoother transition between the layers of the processed radiotherapy headrest. Optionally, the radiotherapy headrest can be polished after the hot melt head completes processing along the processing path. Compared to conventional radiotherapy headrest manufacturing methods, the radiotherapy headrest manufacturing method provided by the present invention sacrifices precision and processing efficiency to make the resulting radiotherapy headrest more economical and more in line with the actual needs of patients. Experiments have shown that the manufacturing method provided by the present invention can control the processing error within 3mm by adjusting the hot melt head processing parameters. However, this error has no effect on the use of the radiotherapy headrest due to the hair on the patient's head, soft tissue, etc., and the actual head has a high degree of fit with the radiotherapy headrest.

[0032] In an embodiment provided by the present invention, obtaining an actual contour model of a patient's head within a first coordinate system includes: performing a tomographic scan of the patient's head using different types of wavelength signals; receiving a reflected signal reflected from the patient's head in response to the wavelength signal; scanning point information including the vertical distance of the scanning point relative to the X-axis, Y-axis, and Z-axis in the first coordinate system; determining the first spatial coordinate point (X, Y, Z) corresponding to each scanning point based on the scanning point information, forming a first point set corresponding to the first spatial coordinate point (X, Y, Z), and then forming an actual contour model from the first point set. This embodiment primarily illustrates how to obtain an actual contour model of a patient within the first coordinate system. The different types of waves may include mechanical waves, electromagnetic waves, and the like.

[0033] The core of the present invention is that the radiotherapy headrest produced by the method for producing the radiotherapy headrest can meet different treatment needs. Now, examples are given in combination with different actual application scenarios.

[0034] In embodiment 1, the bed surface on which the radiotherapy headrest is placed has a certain height, and the bed surface height is the first distance value Z1. The first spatial point (X, Y, Z) is adjusted to obtain the second spatial coordinate point (X, Y, Z-Z1) corresponding to each scanning point, and a second point set corresponding to the second spatial coordinate point (X, Y, Z-Z1) is formed, and the first contour model is reconstructed from the second point set.

[0035] In the second embodiment, the first coordinate system is constructed by taking the width direction of the patient's body as the X-axis, the height direction of the patient as the Y-axis, and the direction between the patient's back and chest as the Z-axis; when the first constraint condition is that the patient's head is tilted relative to the back at an angle β when using a headrest to achieve different types of waves and important organs of the patient's head, the YZ plane formed by the Y-axis and the Z-axis in the first coordinate system is rotated by an angle β, and the second spatial coordinate point (X, Y, Z-Z1) is transformed into a third spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ-Z1), forming a third point set corresponding to the third spatial coordinate point, and the first contour model is reconstructed from the third point set.

[0036] Because the human head contains many important organs that require special protection during radiotherapy, these organs are referred to as "organs at risk," such as the lens, eyes, brainstem, and bone marrow. Radiation during radiotherapy typically occurs in a straight line. By tilting the head at a certain angle relative to the plane of the back, tilting the patient's head at an angle β helps protect these organs at risk. This angle is typically acute, particularly to prevent radiation from directly hitting the lens (the eyeball). Therefore, when manufacturing a radiotherapy headrest, this treatment requirement is taken into account. With the patient's height as the Y-axis, the head is tilted at an angle β. While the patient remains stationary, the first coordinate system is adjusted to change the second spatial coordinate point corresponding to each scan point in the first coordinate system. Multiple third coordinate points are then obtained, ultimately forming a third point set, which is then used to reconstruct the first contour model. Therefore, the radiotherapy headrest manufacturing method provided in this embodiment can customize the radiotherapy headrest based on patient head shape differences. Furthermore, during radiotherapy, the headrest naturally tilts at a certain angle relative to the plane of the back, preventing radiation from directly hitting the lens.

[0037] In the third embodiment, when the first constraint condition is to raise the headrest height h, the third spatial coordinate point is transformed to form a fourth spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ+h-Z1), and the fourth point set corresponding to the fourth spatial coordinate point is reconstructed from the fourth point set into the first contour model. In real life, due to bad eye habits and long hours of desk work, people's heads will tilt forward to varying degrees. Therefore, in the process of making a radiotherapy headrest, the radiotherapy headrest is raised to improve the comfort of the radiotherapy headrest during use, and multiple fourth spatial coordinate points are obtained to form a fourth point set corresponding to the multiple fourth spatial coordinate points. Finally, the fourth point set is reconstructed into the first contour model. Therefore, the radiotherapy headrest manufactured by the manufacturing method of the radiotherapy headrest provided in this embodiment has better radiotherapy comfort.

[0038] In the fourth embodiment, when the first constraint condition is that the patient's tumor grows on one or both sides of the head and needs to be treated in the lateral position, the X-axis and the Z-axis in the first coordinate system are simultaneously rotated 90° in the positive direction and / or 90° in the negative direction around the Y-axis; when the X-axis and the Z-axis are rotated 90° in the positive direction, the fourth spatial coordinate point is transformed to form a fifth spatial point (-Ysinβ-Zcosβ, Ycosβ-Zsinβ, X+h-Z1); when the X-axis and the Z-axis are rotated 90° in the negative direction, the fourth spatial coordinate point is transformed to form a sixth spatial point (Ysinβ+Zcosβ, Ycosβ-Zsinβ, -X+h-Z1); the fifth spatial point and / or the sixth spatial point form a corresponding fifth point set, and the first contour model is reconstructed from the fifth point set. In the actual radiotherapy process, some patients have tumors that grow on one side or both sides of the head, and are asymmetrical and of different sizes. Using unilateral or bilateral decubitus radiotherapy can achieve better radiotherapy effects while avoiding direct radiation on the crystals to prevent radiation damage to the crystals. How to meet the above treatment needs? Example 4 provides a good solution. It also uses the patient himself to remain motionless to adjust the first coordinate system for constructing the first contour model, and then the multiple fourth spatial coordinate points originally in the first coordinate system are transformed into the fifth spatial point and / or the sixth spatial point, and then the fifth point set corresponding to the multiple fifth spatial points and / or the sixth spatial points is formed, and finally the first contour model is reconstructed from the fifth point set. As for whether the fourth spatial coordinate point is transformed into the fifth spatial point, the sixth spatial point, or even the fifth spatial point and the sixth spatial point, it needs to be determined according to the actual treatment needs, that is, whether the treatment needs are whether the tumor grows on the left or right side of the patient, or whether there are tumors on both the left and right sides. Therefore, the radiotherapy headrest manufactured by the manufacturing method of the radiotherapy headrest provided in this embodiment can meet the needs of patients with unilateral or bilateral tumors to avoid direct radiation exposure to the lens during radiotherapy, while also achieving better radiotherapy comfort.

[0039] In addition to being committed to ensuring that the manufactured radiotherapy headrest can meet different treatment needs, the present invention also provides multiple embodiments.

[0040] The second coordinate system has the same orientation as the first coordinate system; at least two layers of processing sub-areas are selected, corresponding to non-overlapping processing paths, and the second sub-area is formed by each processing path. The hot melt head is rotated a certain angle around the Y-axis so that the axis of the hot melt head is always perpendicular to the second sub-area. This ensures that the surface of the radiotherapy headrest has better processing accuracy after processing. In addition to adjusting the hot melt head temperature and processing speed during the processing, the second coordinate system (the hot melt head processing coordinate system) is set to the same orientation as the first coordinate system, ensuring that the processing reference is consistent with the actual contour model and the reference of the reconstructed first contour model, thereby reducing actual processing errors. On the other hand, the above embodiments all use layer-by-layer processing of the processing sub-areas, meaning that the hot melt head only moves along the processing path of one layer of processing sub-areas at a time, and the distance between layers is minimized to achieve a visually approximate curve effect. In reality, the transition between these layers is not smooth. In order to make the transition between layers smoother, at least two processing sub-areas are selected, and a second sub-area is set between the upper and lower intervals of the corresponding non-overlapping processing paths. The hot melt head is rotated around the Y-axis by a certain angle to process the interval area between the processing sub-areas, namely the second sub-area, and the axis of the hot melt head is always perpendicular to the second sub-area.

[0041] Similarly, when manufacturing a unilateral decubitus radiotherapy headrest and / or a bilateral decubitus radiotherapy headrest, the X-axis and Z-axis in the first coordinate system are simultaneously rotated 90° forward and / or 90° reversely around the Y-axis to achieve processing at the upper and lower interval positions of the processing path, making the transition between the upper and lower processing paths of the unilateral decubitus radiotherapy headrest and / or the bilateral decubitus radiotherapy headrest smoother, eliminating the manual polishing step, and improving the surface accuracy and processing efficiency of the radiotherapy headrest.

[0042] In the embodiment provided by the present invention, after obtaining a headrest that is consistent with the outer contour of the first contour model, a first positioning hole is processed on the headrest, and the first positioning hole cooperates with the positioning pin on the bracket that fixes the headrest during radiotherapy of the patient. When making the radiotherapy headrest, the first positioning hole is processed on the headrest, and when the patient is receiving treatment on the radiotherapy bed, the positioning pin on the bracket fixed on the radiotherapy bed is inserted into the first positioning hole, which can achieve rapid positioning of the headrest, so that during radiotherapy, the processing reference of the radiotherapy headrest is consistent with the reference of the radiotherapy equipment. The radiotherapy headrest processed by this manufacturing method can reduce the placement error of the radiotherapy headrest during radiotherapy. By reducing this error, the influence of radiation on the lens and other key organs of the head can be prevented, thereby improving the radiotherapy effect.

[0043] Please Figure 2As shown, the present invention provides a device for making a radiotherapy headrest, which includes a first acquisition module 10, used to obtain an actual contour model of a patient's head in a first coordinate system; a first construction module 20, used to reconstruct the actual contour model into a first contour model based on treatment requirements as a first constraint condition; a first forming module 30, used to segment the first contour model into multiple layers of processing sub-areas according to a preset direction, and orthographically project the first contour model into the processing sub-areas one by one to form a processing path; a first processing module 40, used to fix the headrest blank in a second coordinate system, and a hot melt head processes the headrest blank in the second coordinate system according to the processing path to obtain a headrest consistent with the outer contour of the first contour model. For the technical effects of the device for making the radiotherapy headrest, please refer to the various embodiments of the method for making the radiotherapy headrest, and will not be repeated again.

[0044] The embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other.

[0045] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a radiotherapy headrest, characterized in that: The method comprises: Acquire an actual contour model of the patient's head in a first coordinate system; Reconstructing the actual contour model into a first contour model based on treatment requirements as a first constraint; Segmenting the first contour model into multi-layer processing sub-areas according to a preset direction; orthographically projecting the outer contours of the first contour model onto the corresponding processing sub-areas one by one to form a processing path; The headrest blank is fixed in a second coordinate system, and the hot melt head processes the headrest blank according to the processing path in the second coordinate system to obtain a radiotherapy headrest consistent with the outer contour of the first contour model; The obtaining of the actual contour model of the patient's head in the first coordinate system comprises: Different types of wavelength signals are used to tomographically scan the patient's head; receiving a reflection signal reflected from the patient's head in response to the wavelength signal; The scanning point information includes the vertical distances of the scanning point relative to the X-axis, Y-axis, and Z-axis in the first coordinate system; Determine a first spatial coordinate point (X, Y, Z) corresponding to each scanning point according to information of each scanning point, form a first point set corresponding to the first spatial coordinate point (X, Y, Z), and then form the actual contour model from the first point set; The reconstructing the actual contour model into the first contour model based on the treatment requirement as the first constraint condition includes: When the first constraint condition is that the height of the bed surface on which the radiotherapy headrest is placed is a first distance value Z1, adjusting the first spatial coordinate point (X, Y, Z) to obtain a second spatial coordinate point (X, Y, Z-Z1) corresponding to each scanning point, and forming a second point set corresponding to the second spatial coordinate point (X, Y, Z-Z1), and reconstructing the first contour model from the second point set; The first coordinate system is constructed by taking the patient's body width as the X-axis, the patient's height as the Y-axis, and the direction between the patient's back and chest as the Z-axis; The reconstructing the actual contour model into the first contour model based on the treatment requirement as the first constraint condition further includes: When the first constraint condition is that the patient's head is tilted relative to the back at an angle β when using a headrest to achieve different types of waves and important organs of the patient's head, the YZ plane formed by the Y-axis and the Z-axis in the first coordinate system is rotated by an angle β, and the second spatial coordinate point (X, Y, Z-Z1) is transformed into a third spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ-Z1), forming a third point set corresponding to the third spatial coordinate point, and the first contour model is reconstructed from the third point set.

2. The method for manufacturing a radiotherapy headrest according to claim 1, characterized in that: When the first constraint condition is to increase the headrest height h, the third spatial coordinate point is transformed to form a fourth spatial coordinate point (X, Ycosβ-Zsinβ, Ysinβ+Zcosβ+h-Z1), and a fourth point set corresponding to the fourth spatial coordinate point is reconstructed into the first contour model by the fourth point set.

3. The method for manufacturing a radiotherapy headrest according to claim 2, characterized in that: When the first constraint condition is that the patient's tumor grows on one or both sides of the head and requires treatment in the lateral decubitus position, the X-axis and the Z-axis in the first coordinate system are simultaneously rotated 90° forward and / or 90° backward around the Y-axis; When the X-axis and the Z-axis rotate 90° in the positive direction, the fourth spatial coordinate point is transformed to form the fifth spatial point (-Ysinβ-Zcosβ, Ycosβ-Zsinβ, X+h-Z1); When the X-axis and the Z-axis are rotated 90° in opposite directions, the fourth spatial coordinate point is transformed to form the sixth spatial point (Ysinβ+Zcosβ, Ycosβ-Zsinβ, -X+h-Z1); The fifth spatial point and / or the sixth spatial point form a corresponding fifth point set, and the first contour model is reconstructed from the fifth point set.

4. The method for manufacturing a radiotherapy headrest according to any one of claims 1 to 3, characterized in that: The second coordinate system has the same orientation as the first coordinate system; At least two layers of processing sub-areas are selected, corresponding to non-overlapping processing paths, and a second sub-area is formed by each processing path. The hot melt head is rotated around the Y axis by a certain angle so that the axis of the hot melt head is always perpendicular to the second sub-area.

5. The method for manufacturing a radiotherapy headrest according to claim 3, characterized in that: After obtaining a headrest that is consistent with the outer contour of the first contour model, a first positioning hole is machined on the headrest, and the first positioning hole cooperates with a positioning pin that fixes the headrest on the bracket during radiotherapy of the patient.

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