A measuring device for measuring the rotational output dose of a helical tomotherapy device

Abstract

The present invention discloses a measuring device for the rotational output dose of a helical tomotherapy device, which includes a phantom and a first insertion rod. The first insertion rod slot is arranged in the axial direction of the phantom and is located at the axis of the phantom. The first insertion rod is disposed in the first insertion rod slot and fits with the first insertion rod slot. An electrometer slot is provided in the middle of the first insertion rod. Since the present invention can design the size of the electrometer slot to be the size of the ionization chamber of a conventional electrometer, the universality is increased. Secondly, when measuring the rotational output dose of the helical tomotherapy device, the electrometer is located below the axis of the phantom. After removing the first insertion rod and inserting it upside down, when the first insertion rod is inserted into the first insertion rod slot, the electrometer slot is coaxial with the phantom, which is beneficial to measuring the indexes of the linear moving treatment beam, the changes with the angular position of the device, and the changes with the rotation of the gantry.

Description

Technical Field

[0001] The present invention relates to the technical field of helical tomotherapy, and particularly to a measuring device for the rotational output dose of a helical tomotherapy device, the moving treatment beam of a linear accelerator, and the changes with the angular position of the device and the rotation of the gantry. Background Technique

[0002] Helical tomotherapy is a cancer radiotherapy method relying on the helical tomotherapy system TOMO device, and is one of the most advanced tumor radiotherapy technologies today. The helical tomotherapy device integrates IMRT (intensity-modulated conformal radiotherapy), IGRT (image-guided intensity-modulated conformal radiotherapy), and DGRT (dose-guided intensity-modulated conformal radiotherapy). Its unique design perfectly combines a linear accelerator with a helical CT, breaking through many limitations of traditional accelerators. It performs 360-degree focused tomographic irradiation of tumors under CT guidance, and efficiently and precisely treats malignant tumor patients. Helical tomotherapy realizes the adaptive radiotherapy of tumors, can be applied to various tumors in the whole body, especially has significant advantages in the treatment of multiple lesions and tumors adjacent to important organs or tissues. Under the premise of fully protecting normal organs, this treatment method increases the irradiation dose of the target area, reduces the incidence of complications, and thus improves the cure rate of tumor patients.

[0003] The quality control detection of the helical tomotherapy device is the basis for ensuring accurate radiotherapy. Currently, when detecting the rotational output dose of the helical tomotherapy device, specific phantoms and supporting dosimeters and electrometers are required. The existing phantoms and dosimeters (including electrometers) are all specially made. The diameter of the electrometer slot of the existing phantoms is about 6.5 mm, while the diameters of conventional electrometers have different specifications, and the common one is 12.6 mm. Since the electrometers matched with the existing phantoms are inconsistent with the common ionization chamber diameters, when performing detection, conventional electrometers cannot be used in combination with the existing phantoms. On the one hand, the price of the entire set of equipment for quality control detection is very expensive, which is obviously unaffordable for general inspection and testing institutions. On the other hand, since the phantoms, dosimeters, electrometers, and electrometer slots have specific specifications, if any one is damaged, the entire set of equipment will be scrapped, wasting resources.

[0004] At present, the linear accelerators and helical tomotherapy devices widely used in China are both the main technologies for radiotherapy of cancer. Both the linear accelerator and the helical tomotherapy device can be used to treat complex tumors in any part of the human body. The main types of treatment technologies available for these devices are intensity-modulated radiotherapy (IMRT), intensity-modulated radiotherapy with image guidance (IG-IMRT), three-dimensional conformal radiotherapy (3D CRT), and conventional RT. The linear accelerator head in the device head contains components such as a target, a main collimator, a flattening filter, a universal wedge, an ionization chamber, and an auxiliary collimator. Therefore, these components all contribute to generating a uniform radiation dose and forming a beam according to the contour. Currently, more linear accelerators are used in China than helical tomotherapy devices.

[0005] The electrometer slot of the phantom in the prior art is set at a specific position. However, when measuring the rotational output dose of a helical tomotherapy device, the electrometer should be in different positions. For example, when the electrometer is at the axis, it can detect the stability index of the moving treatment beam of a medical linear accelerator. When the electrometer is below the axis, such as at 0.5 m, it can detect the rotational output dose of the helical tomotherapy device. Due to setting the electrometer slot of the phantom at a specific position in the prior art, the phantom can either be used for the moving treatment beam of a medical linear accelerator, the indexes of changes with the angular position of the device and the changes with the rotation of the gantry, or can only measure the rotational output dose.

[0006] Chinese Patent CN201859218 discloses a measurement phantom. The movable part is a rotating body. The measurement part inside the rotating body includes a replaceable measurement plate. A radiation detector can be installed in the measurement plate. The measurement plate rotates synchronously with the rotating body, and can measure the dose and the distribution of the dose field in different directions in the phantom, so that the dose distribution in different planes of the phantom can be measured through the measurement plate. However, since the movable part of this device cannot be stably positioned at a specific position, when performing quality control detection of a helical tomotherapy device, the measurement accuracy of the rotational output dose of the helical tomotherapy device is not high, and it cannot be used to measure the moving treatment beam of a linear accelerator, the indexes of changes with the angular position of the device and the changes with the rotation of the gantry.

[0007] Those skilled in the art urgently need a measurement device that can both measure the rotational output dose of a helical tomotherapy device, and measure the moving treatment beam of a linear accelerator, the indexes of changes with the angular position of the device and the changes with the rotation of the gantry, and has a high measurement accuracy and can be matched with one or more conventional electrometers for use. Summary of the Invention

[0008] The purpose of the present invention is to provide a measurement device to solve the problems in the prior art.

[0009] To achieve the above purpose, the present invention provides the following technical solutions:

[0010] A measuring device for the rotational output dose of a helical tomotherapy device, comprising a phantom and a first plug

[0011] The first plug slot is arranged in the axial direction of the phantom, and the first plug slot is arranged at the axis of the phantom

[0012] The first plug is arranged in the first plug slot and fits with the first plug slot

[0013] An electrometer slot is arranged in the middle of the first plug

[0014] The size of the electrometer slot can have any number of designs. In particular, the size of the electrometer slot corresponds to one of the sizes of several existing electrometers. Multiple first plugs have electrometer slots with different size specifications, forming a set of accessory combinations, so that the measuring device of the present invention can use electrometers with different size specifications, thereby increasing universality and also saving costs and solving the problem of resource waste. The measuring device can also be used to measure the moving treatment beam of a linear accelerator, the change with the angular position of the device, and the change with the rotation of the gantry

[0015] Preferably, the phantom comprises a first phantom and a second phantom. The first phantom comprises a first plane and a first arc surface, and the second phantom comprises a second plane and a second arc surface

[0016] The first phantom and the second phantom are connected by tightly fitting the first plane and the second plane, so that the first arc surface and the second arc surface are spliced into a circular arc surface

[0017] The first plug slot is arranged between the first phantom and the second phantom

[0018] Furthermore, the first plug slot is formed by surrounding the first phantom and the second phantom

[0019] The first plug slot is less on one side of the first phantom than on one side of the second phantom

[0020] Or the first plug slot is more on one side of the first phantom than on one side of the second phantom

[0021] Furthermore, the center line of the electrometer slot is parallel to the center line of the first plug and is arranged between the center line and the side line of the first plug. After the first plug is inserted into the first plug slot, the electrometer slot and the phantom can be coaxial

[0022] Preferably, the measuring device further comprises a base, and the base comprises a base connecting plate, a first base side plate and a second base side plate. The base connecting plate is connected between the first base side plate and the second base side plate

[0023] On the upper side of the first base side plate, a third arc surface is provided, and on the upper side of the second base side plate, a corresponding fourth arc surface is provided. The mold body is connected to the base by fitting the third arc surface and the fourth arc surface.

[0024] Furthermore, on the upper side of the first base side plate, a fifth arc surface is provided, and the fifth arc surface is arranged outside the third arc surface. On the upper side of the second base side plate, a corresponding sixth arc surface is provided, and the sixth arc surface is arranged outside the fourth arc surface. The mold body is connected between the fifth arc surface and the sixth arc surface.

[0025] Preferably, the electrometer slot includes a metal rod slot and an ionization chamber slot, and the metal rod slot and the ionization chamber slot are coaxial.

[0026] Preferably, a plurality of second plug slots are further provided in the axial direction of the mold body, and the second plug slots are arranged on both sides of the first plug slot.

[0027] Furthermore, the second plug slots are coplanar with the axis of the mold body.

[0028] Preferably, a plurality of indication wire grooves are engraved on the mold body, and the indication wire grooves are symmetrically arranged around the axis of the mold body.

[0029] Furthermore, the measuring device further includes a plurality of second plugs, and the second plugs are sequentially arranged in the corresponding second plug slots and are fitted with the second plug slots.

[0030] Furthermore, black fine lines are engraved in the indication wire grooves.

[0031] The present invention has the following beneficial effects:

[0032] The measuring device of the present invention is arranged in the axial direction of the mold body through the first plug slot, and the first plug slot is arranged at the axis of the mold body, and an electrometer slot is arranged in the middle of the first plug; since the size of the electrometer slot can be designed as the size of the ionization chamber of a conventional electrometer, the measuring device of the present invention is adapted to electrometers of different sizes, increasing the universality. Thereby, costs can be saved and the problem of resource waste can be solved.

[0033] Secondly, the center line of the electrometer slot of the present invention is parallel to the center line of the first plug and is arranged between the center line of the first plug and the side line. When measuring the rotational output dose of the helical tomotherapy device, the electrometer is located below the axis of the mold body, which is beneficial to measuring the rotational output dose of the helical tomotherapy device. When measuring the rotational output dose of the helical tomotherapy device, the first plug is taken out, turned upside down and reinserted, so that after the first plug is inserted into the first plug slot, the electrometer slot is coaxial with the mold body, which is beneficial to measuring the indexes of the linear moving treatment beam, the change with the angular position of the device and the change with the rotation of the gantry. Description of the Drawings

[0034] Figure 1 The first structural schematic diagram of the phantom of the measuring device of the present invention;

[0035] Figure 2 The second structural schematic diagram of the phantom of the measuring device of the present invention;

[0036] Figure 3 The first structural schematic diagram of the measuring device of the present invention;

[0037] Figure 4 The second structural schematic diagram of the measuring device of the present invention;

[0038] Figure 5 The first structural schematic diagram of the base connecting plate of the measuring device of the present invention;

[0039] Figure 6 The second structural schematic diagram of the base connecting plate of the measuring device of the present invention;

[0040] Figure 7 The third structural schematic diagram of the base connecting plate of the measuring device of the present invention;

[0041] Figure 8 The first structural schematic diagram of the first base side plate of the measuring device of the present invention;

[0042] Figure 9 The first structural schematic diagram of the base of the measuring device of the present invention;

[0043] Figure 10 The second structural schematic diagram of the base of the measuring device of the present invention;

[0044] Figure 11 The first structural schematic diagram of the first plug rod of the measuring device of the present invention;

[0045] Figure 12 is Figure 11 The A-A sectional structural schematic diagram of the first plug rod of the measuring device of the present invention;

[0046] Figure 13 The first structural schematic diagram of the second plug rod groove of the measuring device of the present invention;

[0047] In the figure: 1 - the first plug rod groove, 2 - the base connecting plate, 3 - the second plug rod groove, 4 - the first phantom, 5 - the second phantom, 6 - the second plug rod, 7 - the base, 8 - the first plug rod, 9 - the third arc surface, 10 - the fifth arc surface, 11 - the indicating wire groove, 12 - the first base side plate, 13 - the electrometer socket, 14 - the metal rod groove, 15 - the ionization chamber groove. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0049] Referring to Figure 1-13 , a measuring device for the rotational output dose of a tomotherapy device and the moving treatment beam of a linear accelerator, which measures the changes with the angular position of the device and the rotation of the gantry, includes a phantom and a first plug 8.

[0050] The first plug slot 1 is arranged in the axial direction of the phantom, and the first plug slot 1 is arranged at the axis of the phantom.

[0051] The first plug 8 is arranged in the first plug slot 1 and fits with the first plug slot 1.

[0052] An electrometer slot is arranged in the middle of the first plug 8. The size of the electrometer slot corresponds to one of the sizes of a number of ionization chambers.

[0053] The measuring device of the present invention is arranged in the axial direction of the phantom through the first plug slot, and the first plug slot is arranged at the axis of the phantom. An electrometer slot is arranged in the middle of the first plug. Since the size design of the electrometer slot can be designed into different specifications, multiple first plugs can be provided for the measuring device of the present invention. Each first plug can have an electrometer slot with different size specifications, forming a set of accessory combinations, so that the measuring device of the present invention can use electrometers with different size specifications. Multiple first plugs with electrometer slots of one size specification can also be provided for the measuring device of the present invention, thereby increasing the universality and saving costs, and solving the problem of resource waste.

[0054] Preferably, the phantom includes a first phantom 4 and a second phantom 5. The first phantom 4 includes a first plane and a first arc surface, and the second phantom 5 includes a second plane and a second arc surface. The first phantom 4 and the second phantom 5 are connected by closely fitting the first plane and the second plane, so that the first arc surface and the second arc surface are spliced into a circular arc surface. The first plug slot 1 is arranged between the first phantom 4 and the second phantom 5. Further, the first plug slot 1 is formed by surrounding the first phantom 4 and the second phantom 5, and the first plug slot 1 is less on the side of the first phantom 4 than on the side of the second phantom 5, or the first plug slot 1 is more on the side of the first phantom 4 than on the side of the second phantom 5. Further, the center line of the electrometer slot is parallel to the center line of the first plug 8 and is arranged between the center line and the side line of the first plug 8. After the first plug 8 is inserted into the first plug slot 1, the electrometer slot and the phantom can be coaxially arranged. The purpose is that when measuring the rotation output dose of a helical tomotherapy device, the electrometer is below the axis of the phantom, which is beneficial to measuring the rotation output dose of the helical tomotherapy device. When measuring the moving treatment beam of a medical linear accelerator, the change indexes with the change of the angular position of the device and the rotation of the gantry, the first plug is taken out, turned upside down and reinserted, so that after the first plug is inserted into the first plug slot, the electrometer slot and the phantom are coaxially arranged, which is beneficial to measuring the moving treatment beam of the linear accelerator, the change indexes with the change of the angular position of the device and the rotation of the gantry.

[0055] Preferably, the measuring device further includes a base 7. The base 7 includes a base connecting plate 2, a first base side plate 12 and a second base side plate. The base connecting plate 2 is connected between the first base side plate 12 and the second base side plate. A third arc surface 9 is arranged on the upper side of the first base side plate 12, and a corresponding fourth arc surface is arranged on the upper side of the second base side plate. The phantom is connected to the base 7 by fitting the third arc surface 9 and the fourth arc surface. The purpose is that on the one hand, the base connecting plate 2 connects the first base side plate 12 and the second base side plate, which is convenient for use. Using the base of the present invention, the measuring device of the present invention can also be placed in a suitable place. On the other hand, the base connecting plate 2 can prevent the phantom from directly contacting the tested device or apparatus.

[0056]

[0057] ​Further, a fifth arc surface 10 is provided on the upper side of the first base side plate 12. The fifth arc surface 10 is provided outside the third arc surface 9. A corresponding sixth arc surface is provided on the upper side of the second base side plate. The sixth arc surface is provided outside the fourth arc surface. The die body is connected between the fifth arc surface 10 and the sixth arc surface. The purpose is that when the present invention is used, the die body is connected to the base 7 by fitting the third arc surface 9 and the fourth arc surface. Since the third arc surface 9 and the fourth arc surface are arc surfaces and due to gravity, in the up and down direction and in the front and back direction, the positions of the die body and the base are relatively fixed. Then, the die body is connected between the fifth arc surface 10 and the sixth arc surface, so that in the left and right direction, the positions of the die body and the base are relatively fixed.

[0058] Preferably, the electrometer slot includes a metal rod slot 14 and an ionization chamber slot 15. The metal rod slot 14 and the ionization chamber slot 15 are coaxial. The purpose is to ensure that the central axis of the electrometer is parallel to the axis of the die body of the measuring device of the present invention.

[0059] Preferably, a plurality of second plug slots 3 are further provided on the die body in the axial direction. The second plug slots 3 are provided on both sides of the first plug slot 1. The purpose is that the size specifications of the second plug slots 3 are specific, so that a second plug with specific specifications can be used. The second plug can be an electrometer with specific specifications, and is used to set the electrometer with specific specifications at different positions to detect the rotation output dose of the helical tomotherapy device.

[0060] Further, the second plug slot 3 and the axis of the die body are coplanar. The purpose is to set the electrometer with specific specifications at different positions to detect the rotation output dose of the measuring helical tomotherapy device, which is convenient for comparison and reduces errors.

[0061] Preferably, a plurality of indicating wire grooves 11 are engraved on the die body. The indicating wire grooves 11 are symmetrically arranged around the axis of the die body. The purpose is to ensure whether the up, down, left, right, front and back directions of the die body are consistent with the position of the device laser line through the scale lines. The device can be a helical tomotherapy device or a medical linear accelerator.

[0062] Further, the measuring device further includes a plurality of second plugs. The second plugs are sequentially arranged in the corresponding second plug slots 3 and are in accordance with the second plug slots 3.

[0063] Further, black thin lines are engraved in the indicating wire grooves 11. The purpose is to facilitate the precise positioning of the die body by the detection personnel.

[0064] Experimental Example 1 Detection of the Rotation Output Dose of the Helical Tomotherapy Device

[0065] Experimental method: The measurement device of the present invention and the existing Tomo Electrometer phantom are used to detect the rotational output dose of the helical tomotherapy device. The dosimeter selected in the present invention is a conventional dosimeter PTW / TW30013 (0.06 cc), and the dosimeter of the Tomo Electrometer phantom is Tomo Electrometer

[0066] / Standard Imaging A1SL (0.053 cc). The detection condition is SAD = 85 cm, and the planned dose is 150.8 cGy.

[0067] The results are shown in Table 1

[0068] Table 1 Comparison of quality control detection between the measurement device of the present invention and the prior art phantom

[0069]

[0070] As can be seen from Table 1, for the measurement device of the present invention and the existing TomoElectrometer phantom, the deviation of the detection results is within the range of ±1.0%, indicating that the measurement device of the present invention can be fully used as a clinical dose verification tool.

[0071] Experimental Example 2 Detection of the stability index of the moving treatment beam of the linear accelerator

[0072] Experimental method: The measurement device of the present invention is used to detect the stability index of the moving treatment beam of the linear accelerator. The dosimeter selected in the present invention is a conventional dosimeter PTW / TW30013 (0.06 cc), and the planned dose is 200 cGy.

[0073] The results are shown in Table 2

[0074] Table 2 Comparison of the measured value of the measurement device of the present invention with the planned dose value

[0075]

[0076] As can be seen from Table 2, for the measurement device of the present invention, the deviation between the measured value and the planned dose value is within the range of ±1.0%, indicating that the measurement device of the present invention can be used as a verification tool for the stability index of the clinical moving treatment beam of the linear accelerator.

[0077] Experimental Example 3 Detection of the index varying with the angular position of the device

[0078] Experimental method: The measurement device of the present invention is used to detect the index varying with the angular position of the device. The device selected is a linear accelerator. The dosimeter selected in the present invention is a conventional dosimeter PTW / TW30013 (0.06 cc), and the planned dose is 200 cGy.

[0079] The results are shown in Table 3

[0080] Table 3 Comparison between the measured values and the planned dose values of the measuring device of the present invention

[0081]

[0082] As can be seen from Table 3, at different angles of the device, the deviation between the measured values of the measuring device of the present invention and the planned dose values is within the range of ±1.0%, indicating that the measuring device of the present invention can be fully used as a verification tool for the change index of the linear accelerator clinical detection with the change of the device angle position.

[0083] Experimental Example 4 Detection of the change index with the rotation of the gantry

[0084] Experimental method: The measuring device of the present invention is required to detect the change index with the rotation of the gantry. The device selected is a linear accelerator. The dosimeter selected in the present invention is a conventional dosimeter PTW / TW30013 (0.06 cc), and the planned dose is 200 cGy.

[0085] The results are shown in Table 4

[0086] Table 4 Comparison between the measured values and the planned dose values of the measuring device of the present invention

[0087]

[0088] As can be seen from Table 4, in different ranges of the gantry rotation, the deviation between the measured values of the measuring device of the present invention and the planned dose values is within the range of ±1.0%, indicating that the measuring device of the present invention can be fully used as a verification tool for the change index of the linear accelerator clinical detection with the rotation of the gantry.

[0089] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A device for measuring the rotational output dose of a helical tomotherapy device, characterized in that: comprising a mold body and a first plug (8), The first rod insertion slot (1) is arranged in the axial direction of the mold body, and the first rod insertion slot (1) is arranged at the axis of the mold body. The first plug (8) is arranged in the first plug slot (1) and matches the first plug slot (1). An electrometer slot is provided in the middle of the first plug (8); The mold body comprises a first mold body (4) and a second mold body (5), the first mold body (4) comprises a first plane and a first arc surface, and the second mold body (5) comprises a second plane and a second arc surface. The first mold body (4) and the second mold body (5) are connected by closely fitting the first plane and the second plane, so that the first arc surface and the second arc surface are spliced into a circular arc surface. The first rod insertion slot (1) is provided between the first mold body (4) and the second mold body (5); The first rod insertion slot (1) is formed by the first mold body (4) and the second mold body (5). The first rod insertion slot (1) is located on one side of the first mold body (4) less than on one side of the second mold body (5). Alternatively, the first rod insertion slot (1) is located on one side of the first mold body (4) more than on one side of the second mold body (5).

2. The measuring device according to claim 1, characterized in that The center line of the electrometer slot is parallel to the center line of the first plug (8) and is arranged between the center line and the edge line of the first plug (8); after the first plug (8) is inserted into the first plug slot (1), the electrometer slot and the mold body can be coaxial.

3. The measuring device according to claim 1, characterized in that The measuring device further comprises a base (7), the base (7) comprising a base connecting plate (2), a first base side plate (12) and a second base side plate, the base connecting plate (2) being connected between the first base side plate (12) and the second base side plate, A third curved surface (9) is provided on the upper side of the first base side plate (12), and a corresponding fourth curved surface is provided on the upper side of the second base side plate. The mold body is connected to the base (7) by fitting the third curved surface (9) and the fourth curved surface.

4. The measuring device according to claim 3, characterized in that A fifth arc surface (10) is provided on the upper side of the first base side plate (12), and the fifth arc surface (10) is provided outside the third arc surface (9); a corresponding sixth arc surface is provided on the upper side of the second base side plate, and the sixth arc surface is provided outside the fourth arc surface; and the mold body is connected between the fifth arc surface (10) and the sixth arc surface.

5. The measuring device according to claim 1, characterized in that The electrometer slot comprises a metal rod slot (14) and an ionization chamber slot (15), wherein the metal rod slot (14) and the ionization chamber slot (15) are coaxial.

6. The measuring device according to claim 1, characterized in that The mold body is further provided with a plurality of second rod insertion slots (3) in the axial direction, and the second rod insertion slots (3) are arranged on both sides of the first rod insertion slot (1).

7. The measuring device according to claim 6, characterized in that The second rod insertion slot (3) is coplanar with the axis of the mold body.

8. The measuring device according to claim 1, characterized in that The mold body is engraved with a plurality of indicator line grooves (11), and the indicator line grooves (11) are symmetrically arranged around the axis of the mold body.

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