Tumor radiotherapy device capable of automatically reducing field

Abstract

The invention relates to the technical field of radiotherapy devices, in particular to a tumor radiotherapy device capable of automatically reducing the field. The main body is provided with a rotatable suspension beam, a circuit control system is arranged in the main body and is used for controlling the operation of the radiotherapy equipment, and the ray generating device is used for emitting radiotherapy rays to a sickbed below the ray generating device; the multi-leaf grating enables radiotherapy rays to form a set radiation field shape to irradiate the tumor position of a patient on a sickbed after penetrating through a gap through the gap shape generated by the multi-leaf grating, and a relative distance adjusting device is further arranged and used for adjusting the relative distance between the multi-leaf grating in the direction of the radiotherapy rays and the ray generating device. According to the invention, field-shrinking irradiation treatment can be carried out after the size of a tumor is reduced due to full-field irradiation of the tumor, the effect of first-time single-time tumor radiotherapy is improved, and automatic field-shrinking irradiation can be carried out under the condition that the radiation intensity is not changed by some schemes.

Description

Technical Field

[0001] The present invention relates to the technical field of radiotherapy devices, and in particular to an automatic tumor radiation therapy device with a shrinking field. Background Art

[0002] Radiation therapy is the use of high-energy radiation to irradiate the tumor lesion area for treatment. The radiation rays have radiation, and under high-intensity radiation conditions, tumor cells die, thereby achieving the removal of the tumor.

[0003] Before radiotherapy, the human body needs to be positioned first. Existing positioning methods mostly use thermoplastic film to achieve repeatability of human posture. Then CT scan is performed on the patient in the positioned posture. Professional personnel outline the target area of ​​the radiotherapy process based on the CT image of the tumor area. The outlined target area image boundary should try to avoid normal tissues and important organs of the human body. During each treatment, the doctor generally outlines multiple corresponding target area images from different angles.

[0004] During the treatment process, the radiotherapy equipment can emit radiation to irradiate the human body through the radiation generating device. The radiotherapy equipment also has a multi-leaf grating used in conjunction with the radiation generating device. The multi-leaf grating can control its own slit shape according to the obtained target area image. When the radiation passes through the slit, a radiation field shape similar to the slit is formed, thereby achieving precise irradiation of the tumor site in the human body. The tumor tissue is affected by the biological effects after radiation irradiation, and its tumor volume gradually decreases. At this time, if the tumor area is continuously irradiated according to the originally set target area image, the surrounding normal tissue will be damaged due to the original large radiation field area. Therefore, the existing treatment method is to perform CT again, use the CT image to re-outline the target area image, and then perform the next radiotherapy.

[0005] Obviously, after the tumor becomes smaller, in order to avoid damage to normal tissue caused by the original large radiation field, the radiotherapy process can only be stopped, the target area image can be redrawn to irradiate the tumor tissue. The time interval between the two radiotherapy treatments is long, which can easily lead to the tumor tissue's increased tolerance to radiation, and thus the subsequent radiotherapy effect will gradually deteriorate.

[0006] The existing technology also has solutions that can achieve automatic field reduction during irradiation. For example, a Chinese patent with authorization announcement number CN102430208B discloses an automatic field reduction tumor radiotherapy device, which mainly reduces the relative distance between the treatment head and the treatment bed by adding a lifting device. More specifically, during the radiotherapy process, the irradiation field area is changed by dynamically adjusting the source-skin distance (the distance between the radiation source and the skin), thereby achieving a single full-field radiotherapy accompanied by a field reduction radiotherapy function, thereby increasing the effect of the first radiotherapy.

[0007] However, the above scheme has the disadvantage that, although the relative distance between the treatment head and the treatment bed is reduced by the lifting device, the area of ​​the irradiation field can be reduced, but the reduction of the source-skin distance also increases the radiation intensity of the human skin. The radiation intensity of the ray is inversely proportional to the square of the distance (the radiation intensity will gradually decay when the ray propagates in the air), that is, the radiation intensity of the ray is inversely proportional to the square of the source-skin distance. Therefore, the field reduction is achieved by reducing the source-skin distance, which will make the radiation intensity of the normal tissue above the tumor tissue stronger than the radiation intensity when the field reduction irradiation is not performed. In the existing tumor treatment process, it is necessary to strictly control the irradiation dose each time, which can be expressed as D=f*t, where f represents the radiation intensity in gray per second, t represents the irradiation time in seconds, and D represents the irradiation dose. Therefore, when the field reduction irradiation is performed by changing the source-skin distance, the radiation intensity changes due to the change in the source-skin distance. In order to ensure that the irradiation dose remains unchanged, it is necessary to perform complex calculations to obtain the radiation intensity after the field reduction, so as to control the irradiation time so as to keep the irradiation dose according to the preset value of the doctor for treatment. Summary of the invention

[0008] The present invention provides an automatic field reduction tumor radiotherapy device, which can perform field reduction irradiation treatment after the tumor volume is reduced by full field irradiation, thereby improving the effect of single tumor radiotherapy, and some schemes can also perform automatic field reduction irradiation without changing the radiation intensity.

[0009] The technical problem solved by the present invention is achieved by adopting the following technical solutions: The present invention provides an automatic field-shrinking tumor radiotherapy device, comprising: a main body, wherein the main body has a rotatable cantilever beam, wherein the interior of the main body has a circuit control system for controlling the operation of the radiotherapy device, a ray generating device, wherein the ray generating device is installed on the cantilever beam and is used to emit radiotherapy rays to a patient's bed position below the ray generating device; a multi-leaf grating, which is located at the radiotherapy ray output end of the ray generating device and, through the slit shape generated by itself, forms a set field shape after the radiotherapy rays pass through the slit to irradiate the tumor position of the patient on the bed; and a relative distance adjusting device, which is used to adjust the relative distance between the multi-leaf grating and the ray generating device along the direction of the radiotherapy rays, thereby changing the size of the field shape formed after the radiotherapy rays pass through the slit.

[0010] Preferably, after the full-field irradiation therapy causes the tumor tissue volume to decrease, the circuit control system inside the main body controls the operation of the relative distance adjustment device so that the relative distance between the multi-leaf grating and the ray generating device along the direction of the radiotherapy ray increases, thereby achieving automatic field reduction.

[0011] Preferably, the relative distance adjustment device is a first lifting device capable of adjusting the position of the multi-leaf grating.

[0012] Preferably, the relative distance adjustment device is a first lifting device capable of adjusting the position of the ray generating device.

[0013] Preferably, the relative distance adjustment device is a first lifting device capable of adjusting the position of the radiation generating device and a second lifting device capable of adjusting the hospital bed synchronously and in the same direction according to the first lifting device.

[0014] Preferably, the first lifting device is a telescopic rod with a fixed end mounted on the suspension beam.

[0015] Preferably, the multi-leaf grating comprises a mounting frame, two groups of opposing linear array blades located inside the mounting frame, and a driving member mounted outside the frame for driving the blades inside the frame to move.

[0016] Preferably, the blades are made of tungsten alloy.

[0017] The beneficial effect of the present invention is that it adjusts the relative distance between the multi-leaf grating and the ray generating device in the direction of the radiotherapy ray by setting a relative distance adjustment device, so as to achieve the adjustment of the shape and size of the irradiation field. After the tumor tissue is reduced, the shrunken ray is used to avoid the healthy tissue around the tumor tissue as much as possible while continuing to irradiate the tumor, thereby improving the effect of a single tumor radiotherapy.

[0018] The radiation field can be adjusted by changing the relative distance between the multileaf grating and the radiation generating device, especially by adjusting the position of the multileaf grating to achieve the effect of shrinking the radiation field. This can ensure that the radiation intensity of the radiation on the irradiated part of the human body remains unchanged without changing the source-skin distance, thereby facilitating the control of the total radiation dose. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 It is a three-dimensional structural schematic diagram of the present invention: Figure 2 It is a cross-sectional schematic diagram of the present invention; Figure 3 It is a schematic diagram of the structure of the ray generating device of the present invention cooperating with the multi-leaf grating to form rays of a specific shape; Figure 4It is a schematic diagram of the multi-leaf grating structure of the present invention; Figure 5 It is a structural schematic diagram of the first embodiment of the present invention; Figure 6 is a schematic structural diagram of a second embodiment of the present invention; Figure 7 It is a structural schematic diagram of the radiotherapy process of the present invention.

[0021] In the figure, 1, hospital bed; 2, main body; 3, suspension beam; 4, ray generating device; 5, multi-leaf grating; 501, gap; 502, driving member; 503, blade; 504, frame; 6, first lifting device; 7, supporting device. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific diagrams.

[0023] refer to Figure 1 and Figure 2 In order to enable those skilled in the art to know the differences between the present invention and the prior art, the common points between the present invention and the prior art are first introduced. The existing tumor radiotherapy device includes a main body 2, a ray generating device 4 and a multi-leaf grating 5, wherein the main body 2 has a circuit control system inside for controlling the operation of the radiotherapy device and a rotatable suspension beam 3 is provided on one side of the main body 2, and the ray generating device 4 is installed on the suspension beam 3 for emitting radiotherapy rays to the position of the bed 1 below, such as Figure 3 As shown, the multileaf grating 5 is at the output end of the ray generating device 4, and the slit 501 shape generated by itself allows the radiotherapy ray A3 to pass through the slit 501 to form a set radiation field shape to irradiate the tumor position of the patient on the bed 1, as shown in FIG. Figure 7 As shown, during the treatment process, the patient lies on the bed 1 in a specific position, and the circuit control system inside the host controls the rotation angle of the suspension beam 3, the emission of radiation by the radiation generating device 4, and the formation of a specific shape of the slit 501 by the multi-leaf grating 5, so as to ensure that the radiation irradiates the tumor at a specific irradiation angle and a radiation field of the shape of the target area image drawn in advance, so as to achieve the treatment effect. The above is the process of tumor treatment by the existing tumor radiotherapy device. In order for those skilled in the art to better understand the principle of the tumor radiotherapy device, the principle structure of the existing multi-leaf grating 5 is further described here, as shown in FIG. Figure 4As shown, the multi-leaf grating 5 includes a mounting frame 504, two groups of opposing and linear array blades 503 inside the mounting frame 504, and a driving member 502 mounted outside the frame 504 for driving the blades 503 inside the frame 504 to move. The driving member 502 drives the multiple blades 503 inside the frame 504 to move, so that a gap 501 is generated inside the multi-leaf grating 5. After the rays pass through the gap 501, a field shape similar to the shape of the gap 501 is formed. The existing multi-leaf grating 5 defines the field shape more accurately, with an accuracy of up to 0.2 mm. The material of the multi-leaf grating 5 is mostly made of tungsten alloy, which can block and shield the rays from radiation.

[0024] The existing tumor radiotherapy devices have the following shortcomings: first, the tumor tissue is affected by the biological effects after radiation irradiation, and its tumor volume gradually decreases. At this time, if the tumor area is continuously irradiated according to the originally set target area image, the surrounding normal tissue will be damaged due to the original large irradiation field area. Secondly, although some existing schemes also have the effect of automatically reducing the field by controlling the reduction of the source-skin distance through the lifting device after full-field irradiation, the radiation intensity of the rays will increase after the source-skin distance is reduced, making it difficult to accurately control the total irradiation dose during the radiotherapy process.

[0025] Based on this, the present invention provides an automatic field shrinking tumor radiotherapy device, which includes a main body 2, a ray generating device 4 and a multi-leaf grating 5 with the same functions as the prior art, and adds a relative distance adjustment device on the basis of the above-mentioned prior art. The relative distance adjustment device is used to adjust the relative distance between the multi-leaf grating 5 and the ray generating device 4 along the direction of the radiotherapy ray, thereby changing the shape and size of the field formed after the radiotherapy ray passes through the gap 501. During the treatment process, the tumor tissue is firstly irradiated with the whole field from multiple angles according to the target area image drawn by the doctor. The treatment process is the same as the treatment process of the prior art. After the tumor tissue is irradiated with the ray and its volume is reduced, the distance between the multi-leaf grating 5 and the ray generating device 4 in the direction of the radiation ray is adjusted by the relative distance adjustment device, thereby realizing the adjustment of the shape and size of multiple fields.

[0026] Specifically, the relative distance adjustment device performs control actions through the circuit control system inside the main body 2, so that the relative distance between the multi-leaf grating 5 and the ray generating device 4 along the direction of the radiotherapy ray increases, thereby achieving automatic field shrinkage.

[0027] like Figure 5As shown, a first embodiment of an automatic field reduction tumor radiotherapy device provided by the present invention is introduced, wherein the relative distance adjustment device is a first lifting device 6 capable of adjusting the position of the multi-leaf grating 5, that is, during treatment, the tumor tissue is firstly irradiated in the whole field according to the image drawn by the professional, and when the whole field irradiation is completed, the multi-leaf grating 5 is driven by the first lifting device 6 to move along the radiation direction in the direction away from the radiation generating device 4 (the position of the radiation generating device 4 remains unchanged), so that the radiation is reduced in field (during the field reduction treatment, the shape of the slit 501 of the multi-leaf grating 5 is the same as the shape of the slit 501 during the full field treatment, that is, the obtained field reduction shape and the full field shape are similar patterns of different sizes, and because the center points of the field reduction shape and the full field shape are not changed, it can be ensured that during the field reduction irradiation, the radiation irradiates the central part of the tumor tissue, thereby improving the effect of the first radiotherapy). It needs to be further described that Figure 5 The structure adopted by the first lifting device 6 is a telescopic rod, the fixed end of the telescopic rod is on the suspension beam 3, and the movable end of the telescopic rod is fixed to the multi-leaf grating 5. The effect of shrinking the field is achieved by extending the telescopic rod. Although the telescopic rod is used as an example in the embodiment, other device structures can also be used to replace the telescopic rod in the specific production process, such as the common screw drive structure, as long as the position adjustment of the multi-leaf grating 5 can be achieved. Similarly, the fixed end of the first lifting device 6 can also be fixed at other positions, such as on the shell of the ray generating device 4. The following embodiments also do not limit the specific structure of the first lifting device 6 and the installation position of the fixed end.

[0028] like Figure 6 As shown, the second embodiment of the tumor radiotherapy device with automatic field shrinkage provided by the present invention is introduced. Compared with the first embodiment, the second embodiment is different in that the movable end of the first lifting device 6 is fixed to the ray generating device 4, the position of the multi-leaf grating 5 remains unchanged, and the first lifting device 6 drives the ray generating device 4 to move ( Figure 6 The ray generating device 4 and the multi-leaf grating 5 move away from each other, thereby achieving a shrinking field effect.

[0029] Compared with the above two embodiments, in the first embodiment, the position of the multi-leaf grating 5 is changed by the first lifting device 6, and the position of the ray generating device 4 remains unchanged, so that the distance between the multi-leaf grating 5 and the ray generating device 4 is increased, thereby achieving the effect of shrinking the field of view; while in the second embodiment, the position of the ray generating device 4 is changed by the first lifting device 6, and the position of the multi-leaf grating 5 remains unchanged, so that the distance between the multi-leaf grating 5 and the ray generating device 4 is increased, thereby achieving the effect of shrinking the field of view. Although both of them achieve the effect of shrinking the field of view, in the first embodiment, compared with the second embodiment, the position of the ray generating device 4 relative to the position of the hospital bed 1 remains unchanged, so the source-skin distance (the source-skin distance is the distance between the ray generating device 4 and the human skin) remains unchanged, and the radiation intensity of the ray to the human body before and after the field of view shrinkage remains unchanged, which makes it easier to control the total irradiation dose of the radiotherapy process. In the second embodiment, since the movement of the ray generating device 4 is controlled, the position of the ray generating device 4 relative to the hospital bed 1 is changed. Figure 6 In the embodiment, the radiation generating device 4 moves upward, resulting in an increase in the source-skin distance value. When the radiation propagates in the air, its radiation intensity will gradually decay (it is well known that the radiation intensity is inversely proportional to the square of the distance, that is, the farther the distance, the smaller the radiation intensity). Therefore, in the second embodiment, the radiation intensity will decrease after the field is reduced. Therefore, in order to avoid the change in radiation intensity before and after the field is reduced, which may make the radiation dose of the human body difficult to control, it is preferred to use the first embodiment for field reduction treatment.

[0030] On the basis of the above-mentioned first and second embodiments, those skilled in the art can easily think of the third embodiment of the present invention, that is, the relative distance adjustment device is still the first lifting device 6 capable of adjusting the ray generating device 4, and its improvement over the second embodiment is that it also has a second lifting device capable of synchronously and unidirectionally adjusting the bed 1 according to the first lifting device 6, that is, the difference between the third embodiment and the second embodiment is that the supporting device 7 under the bed 1 is changed to a second lifting device, and when the first lifting device 6 drives the ray generating device 4 to move upward, the second lifting device drives the bed 1 to move upward synchronously, thereby avoiding the value change of the source-skin distance during the process of shrinking the field, and ensuring that the radiation intensity of the ray does not change before and after the shrinking field. It should be noted that the third embodiment shrinks the field without changing the source-skin distance, and is only applicable to the case where the ray is irradiated vertically downward, that is, in the case of Figure 7 In the S1 state, the angle is relatively stable when irradiated at other angles, such as Figure 7 In the irradiation angles of S2 and S3, since the bed 1 can only compensate for the displacement of the radiation generating device 4 in the vertical direction through the second lifting device, the source-skin distance is still in an increasing state when irradiating at the angles of S2 and S3, that is, the radiation intensity of the rays will be enhanced in the S2 and S3 states.

[0031] In summary, compared with the above three embodiments, the first embodiment is the best choice. It can achieve reduced field irradiation by only controlling the position of the multi-leaf collimator 5 (the first lifting device 6 controls it to move away from the ray generating device 4 along the direction of the ray). That is, during the treatment process, Figure 7 As shown, three radiation angles of the tumor radiotherapy device during the treatment process are shown. When the three radiation angles are working, the shape of the gap 501 generated inside the multileaf grating 5 is preset (set according to the target area pattern outlined by professionals based on the CT image). After the radiotherapy ray A3 passes through the gap 501, it forms a radiation field shape of a preset shape to irradiate the tumor tissue. During the irradiation process, since the tumor tissue will shrink under the action of the biological effect, the healthy cells around the tumor tissue are prevented from being irradiated by the radiation. Through the internal circuit control system of the main body 2, the relative distance between the multileaf grating 5 and the ray generating device 4 is controlled to achieve field reduction (the field shape after field reduction is similar to the field shape before field reduction, but the size is different), and then the healthy tissue around the tumor tissue is avoided (the shape of the shrunken tumor tissue is very similar to that of the non-shrunken tumor tissue), and the shrunken tumor tissue is continuously irradiated according to the three radiation angles, which can improve the treatment effect of the first radiotherapy. It should be noted that the irradiation angles in the actual treatment process are not necessarily three, and there may be more or fewer irradiation angles, which are set according to the patient's condition.

[0032] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An automatic field reduction tumor radiotherapy device, comprising: A main body (2), the main body (2) having a rotatable suspension beam (3), and the interior of the main body (2) having a circuit control system for controlling the operation of the radiotherapy device; A ray generating device (4), the ray generating device (4) being mounted on the suspension beam (3) and used for emitting radiotherapy rays towards the position of the patient bed (1) below the suspension beam; The multi-leaf grating (5) is located at the radiotherapy ray output end of the ray generating device (4), and the slit (501) shape generated by the multi-leaf grating enables the radiotherapy ray to pass through the slit (501) to form a set radiation field shape to irradiate the tumor position of the patient on the bed (1); It is characterized in that Also includes The relative distance adjustment device is used to adjust the relative distance between the multileaf grating (5) and the ray generating device (4) along the direction of the radiotherapy ray, thereby changing the shape and size of the radiation field formed after the radiotherapy ray passes through the slit (501).

2. The automatic tumor radiation therapy device with shrinking field according to claim 1, characterized in that: After the tumor tissue volume is reduced due to full-field irradiation therapy, the circuit control system inside the main body (2) controls the operation of the relative distance adjustment device so that the relative distance between the multi-leaf grating (5) and the ray generating device (4) along the direction of the radiotherapy ray increases, thereby achieving automatic field reduction.

3. The automatic tumor radiation therapy device with shrinking field according to claim 1, characterized in that: The relative distance adjustment device is a first lifting device (6) capable of adjusting the position of the multi-leaf grating (5).

4. The automatic tumor radiation therapy device with shrinking field according to claim 1, characterized in that: The relative distance adjustment device is a first lifting device (6) capable of adjusting the position of the ray generating device (4).

5. The automatic tumor radiation therapy device with shrinking field according to claim 1, characterized in that: The relative distance adjustment device comprises a first lifting device (6) capable of adjusting the position of the ray generating device (4) and a second lifting device capable of synchronously and equidirectionally adjusting the hospital bed (1) according to the first lifting device (6).

6. The automatic tumor radiation therapy device with shrinking field according to any one of claims 2 to 4, characterized in that: The first lifting device (6) is a telescopic rod with a fixed end mounted on the suspension beam (3).

7. The automatic tumor radiation therapy device with shrinking field according to claim 1, characterized in that: The multi-leaf grating (5) comprises a mounting frame (504), two groups of opposing and linearly arrayed blades (503) located inside the mounting frame (504), and a driving member (502) mounted outside the frame (504) for driving the blades (503) inside the frame (504) to move.

8. The automatic tumor radiation therapy device with shrinking field according to claim 7, characterized in that: The blade (503) is made of tungsten alloy.

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