WO2021040213A1 - Real-time dose monitoring system and real-time dose monitoring method using plastic fluorescent plate - Google Patents

Abstract

The present invention relates to a real-time dose monitoring system and a real-time dose monitoring method which use a plastic fluorescent plate, wherein the system may comprise: the plastic fluorescent plate located in front of a gantry of a radiation therapy apparatus to transmit radiation irradiated by the radiation therapy apparatus and generate visible light corresponding to an amount of transmitted radiation; a camera for acquiring a dose distribution by capturing an image of the plastic fluorescent plate; and a processor for measuring and outputting a dose on the basis of the size and color of a visible light generation area of the dose distribution.

Description

Real-time dose monitoring system and method using plastic fluorescent plate

The present invention relates to a system and method for real-time dose monitoring using a plastic fluorescent plate that enables real-time dose monitoring of a radiation therapy device more simply and accurately by using a plastic fluorescent plate that generates visible light corresponding to a dose transmitted.

The number of patients diagnosed with cancer is steadily increasing, and treatment is progressed through surgery, chemotherapy and radiation therapy. Among these, radiotherapy has the advantage of less pain and outpatient treatment to the patient during treatment, but if the planned dose is not delivered correctly, there is a risk that cancer treatment is not performed properly and the surrounding normal tissues are damaged.

Until now, a system that verifies the dose in real time by attaching a fluorescent plate to the gantry has not been developed or commercialized. In particular, in the case of particle ray therapy, a system that verifies the dose in real time by attaching it to the gantry even when other dose measuring devices are used. Nothing has been reported. Therefore, if the technology in this field is developed, it is expected to preempt the technology and have a large technical ripple effect on research and development of other dose verification systems in the future.

On the other hand, although there is a system for verifying the treatment beam inside the radiation therapy device, it is difficult to verify the precise distribution of the treatment beam due to low resolution.

And in the case of particle ray therapy, there are cases where very precise treatment is performed using a scanning technique. This treatment technique is difficult to accurately verify by the internal verification system. In addition, if double verification using an independent verification system other than the internal verification system, verification of the treatment beam will be made more accurately.

Accordingly, as to solve the above problems, the present invention is to provide a real-time dose monitoring system and method using a plastic fluorescent plate that can maximize the monitoring performance while minimizing the implementation cost by using a plastic fluorescent plate.

In addition, it is intended to provide a real-time dose monitoring system and method using a plastic fluorescent plate that enables a radiation therapy device to perform a dose monitoring operation independently.

The object of the present invention is not limited to the above-mentioned object, and other objects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

As a means for solving the above problems, according to an embodiment of the present invention, a plastic fluorescent plate which is located in front of the gantry of the radiation treatment device, transmits the radiation irradiated by the radiation treatment device and generates visible light corresponding to the amount of radiation transmitted; A camera that captures an image of the plastic fluorescent plate to obtain a dose distribution map; And it provides a real-time dose monitoring system using a plastic fluorescent plate including a processor for measuring and outputting the dose based on the size and color of the visible light generation area of the dose distribution map.

The real-time dose monitoring system is further characterized in that it further comprises a mirror for adjusting the viewing angle of the camera.

The processor may further include a function of comparing the dose measured amount with a dose setting value, and then stopping driving the radiation therapy device or generating and outputting an alarm signal for operator notification when there is a discrepancy.

In addition, the processor compares the dose measurement amount with a dose setting value, calculates a dose reduction amount due to insertion of a plastic fluorescent plate, and then calculates a radiation output adjustment amount based on the dose reduction amount, and provides the function to the radiation therapy device or treatment planning system. It characterized in that it further includes.

In addition, the processor may further include a function of checking and notifying the abnormal operation of the radiation therapy device when the dose measurement amount does not change according to the radiation output adjustment amount.

As a means for solving the above problem, according to another embodiment of the present invention, when a plastic fluorescent plate is positioned in front of a gantry of a radiation treatment device, allowing the radiation treatment device to be driven; When the radiation therapy device is driven to generate visible light corresponding to the amount of radiation transmitted to the plastic fluorescent plate, taking an image of the plastic fluorescent plate to obtain a dose distribution map; And it provides a real-time dose monitoring method using a plastic fluorescent plate comprising the step of measuring and notifying the dose based on the size and color of the visible light generation area of the dose distribution map.

The real-time dose monitoring method further includes the step of comparing the dose measured amount with the dose setting value, and then stopping driving the radiation therapy device or generating and outputting an alarm signal for operator notification when there is a discrepancy.

In addition, the real-time dose monitoring method compares the dose measured with the dose set value to calculate the dose reduction amount due to the insertion of the plastic fluorescent plate, and then calculates a radiation output adjustment amount based on the dose reduction amount and provides it to the radiation therapy device or treatment planning system. It characterized in that it further comprises the step of.

In the present invention, a plastic fluorescent plate that generates visible light corresponding to the amount of radiation transmitted is attached to the front of a gantry of a radiation treatment device and image-processed to monitor the dose of the radiation treatment device in real time. In addition, based on the high resolution of the plastic fluorescent plate, the dose of the oblique treatment device can be more precisely monitored.

In addition, the real-time dose monitoring system and method using the plastic fluorescent plate of the present invention is implemented as a device independent from the existing radiation therapy device, so that the subsequent dose is used together with the internal verification system of the radiation therapy device to perform a double verification operation. To be there. In other words, the verification of the dose can be made more accurately.

1 is a view showing a real-time dose monitoring system using a plastic fluorescent plate according to an embodiment of the present invention.

2 is a diagram showing a real-time dose monitoring system using a plastic fluorescent plate according to another embodiment of the present invention.

3 is a view showing a real-time dose monitoring system using a plastic fluorescent plate according to another embodiment of the present invention.

FIG. 4 is a diagram showing a result of dose measurement using a plastic fluorescent plate, and the radiation at this time may be a particularly proton therapy beam.

5 is a view for explaining the performance of a real-time dose monitoring system according to an embodiment of the present invention.

6 is a view for explaining a real-time dose monitoring method using a plastic fluorescent plate according to an embodiment of the present invention.

7 is a view for explaining a real-time dose monitoring method using a plastic fluorescent plate according to another embodiment of the present invention.

The following content merely exemplifies the principles of the present invention. Therefore, those skilled in the art can implement the principles of the present invention and invent various devices included in the concept and scope of the present invention, although not clearly described or illustrated herein. In addition, it is understood that all conditional terms and examples listed in this specification are, in principle, expressly intended only for the purpose of making the concept of the present invention understood, and are not limited to the embodiments and states specifically listed as such. It should be.

In addition, it is to be understood that all detailed descriptions listing specific embodiments as well as principles, aspects and embodiments of the present invention are intended to include structural and functional equivalents of these matters. It should also be understood that these equivalents include not only currently known equivalents, but also equivalents to be developed in the future, that is, all devices invented to perform the same function regardless of the structure.

Thus, for example, the block diagrams herein are to be understood as representing a conceptual perspective of exemplary circuits embodying the principles of the invention. Similarly, all flowcharts, state transition diagrams, pseudocodes, etc. are understood to represent the various processes performed by a computer or processor, whether or not the computer or processor is clearly depicted and that can be represented substantially in a computer-readable medium. It should be.

The functions of the various elements shown in the drawings, including a processor or functional block represented by a similar concept, may be provided by the use of dedicated hardware as well as hardware having the ability to execute software in association with appropriate software. When provided by a processor, the function may be provided by a single dedicated processor, a single shared processor, or a plurality of individual processors, some of which may be shared.

In addition, the explicit use of terms presented as processor, control, or similar concepts should not be interpreted exclusively by quoting hardware capable of executing software, and without limitation, digital signal processor (DSP) hardware, ROM for storing software. It should be understood to implicitly include (ROM), RAM (RAM) and non-volatile memory. Other commonly used hardware may also be included.

In the claims of the present specification, components expressed as means for performing the functions described in the detailed description include all types of software including, for example, combinations of circuit elements or firmware/microcodes that perform the above functions. It is intended to include all methods of performing a function to perform the function, and is combined with suitable circuitry for executing the software to perform the function. Since the invention defined by these claims is combined with the functions provided by the various enumerated means and combined with the manner required by the claims, any means capable of providing the above functions are equivalent to those conceived from this specification. It should be understood as.

The above-described objects, features, and advantages will become more apparent through the following detailed description in connection with the accompanying drawings, whereby those of ordinary skill in the technical field to which the present invention pertains can easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 is a view showing a real-time dose monitoring system using a plastic fluorescent plate according to an embodiment of the present invention.

Referring to FIG. 1, the real-time dose monitoring system 100 of the present invention includes a plastic fluorescent plate insertion tray 110, a plastic fluorescent plate 120, a camera 130, a processor 140, and the like, and a radiation therapy device ( 210) and is implemented in a separate device type.

The plastic fluorescent plate insertion tray 110 is attached to the front of the gantry of the radiation therapy device 210 so that the plastic fluorescent plate 120 can be inserted and fixed later. In this case, the radiation therapy device 210 may be a proton therapy device, a heavy particle therapy device, or the like.

The plastic fluorescent plate 120 reacts with high-energy radiation irradiated by a radiation therapy device and converts it into visible light. That is, while transmitting the radiation, visible light corresponding to the amount of radiation transmitted is generated.

It is implemented in a plate shape having the same shape and size as the gantry, and can be inserted and fixed in the plastic fluorescent plate insertion tray 110, and manufactured with EJ-212, NE-102A, BC-400, etc. having the physical properties shown in Table 1. It is possible.

Light output (% Anthracene)	65
Scintillation efficiency (photons/1 MeV e-)	10,000
Wavelength of maximum emission (nm)	423
Rise time (ns)	0.9
Decay time (ns)	2.4
Pulse width, FWHM (ns)	2.7
Polymer base	Polyvinyltoluene
Density (g/cm 3 )	1.023

The camera 130 captures an image of a plastic fluorescent plate to obtain a dose distribution map. The processor 140 obtains information on the correlation between the visible light color and the dose in advance, and measures and reports the current dose based on the size and color of the visible light generation area of the dose distribution map.

In addition, the processor 140 receives and stores information on the dose setting value from the treatment planning system 200 that establishes and reports a patient treatment plan, and immediately stops the radiation treatment when the currently measured dose distribution is different from the dose setting value. To ensure the stability of the treatment.

In addition, the processor 140 considers that the dose may be reduced due to the insertion of the plastic fluorescent plate, and calculates a radiation output adjustment amount based on the dose reduction amount by as much as based on the dose reduction amount by the plastic fluorescent plate. It may also be provided to the planning system. That is, by increasing the radiation output amount of the radiation treatment device 210 by the amount of reduction in dose by the plastic fluorescent plate through the radiation treatment device or the treatment planning system, the dose finally provided to the patient can be guaranteed an initial set value.

In addition, in the above description, the camera 130 and the processor 140 of the present invention may be implemented as a device located outside the radiation treatment device, but if necessary, the camera 130 and the processor 140 may be implemented in the form of a device built into the radiation treatment device as shown in FIG. Yes, of course.

In addition, as shown in FIG. 3, the real-time dose monitoring system 100 of the present invention further includes a mirror 150 for reflecting the plastic fluorescent plate illuminated on itself toward the photographing direction of the camera, and thereby the viewing angle of the camera 130 It can be arbitrarily adjusted.

At this time, the arrangement position and inclination angle of the mirror 150 may be determined according to the relative position and angle of the gantry and the camera. For example, assuming that the camera is positioned on the lower left of the gantry, the mirror 150 is positioned vertically below the gantry and to the horizontal left of the camera, and may have an inclination angle of 45°.

FIG. 4 is a diagram showing a result of dose measurement using a plastic fluorescent plate, and the radiation at this time may be a particularly proton therapy beam.

Referring to Figure 4 (a), the plastic fluorescent plate of the present invention can measure the spot of radiation (for example, a proton beam) requiring precise measurement at a level similar to that of the high-resolution film (EBT3), and generated light It can be seen that the amount of is proportional to the delivered dose and has excellent reproducibility.

Referring to (b) of FIG. 4, since the plastic fluorescent plate has linearity with respect to the dose, it can be seen that the present invention can trace back to the dose based on the amount of light generated by the fluorescent plate, that is, the color of visible light. .

Finally, as shown in (c) of Figure 4, it can be seen that the measurement reproducibility of the plastic fluorescent plate is also very high. As a result, it can be seen that the radiation distribution calculated by the treatment planning system can be verified with high reliability with a fluorescent plate-based measurement system.

5 is a view for explaining the performance of a real-time dose monitoring system according to an embodiment of the present invention.

Figure 5 (a) is the dose measurement result of the real-time dose monitoring system, (b) is the dose setting value of the treatment planning system, comparing this, the plastic fluorescent plate of the present invention will ensure very high measurement reproducibility as described above. You can see that you can.

FIG. 5C is a diagram showing the gamma distribution, and the comparison between the dose measurement value using a fluorescent plate and the treatment planning system has a very high gamma pass rate of 98.5% based on 3%/3 mm. And, if the gamma value of 3%/3 mm is less than 1, it is passed, and if it is greater than 1, it is confirmed and notified that it is failure.

6 is a view for explaining a real-time dose monitoring method using a plastic fluorescent plate according to an embodiment of the present invention.

First, after placing the plastic fluorescent plate 120 in front of the gantry of the radiation therapy device (S1), taking a picture over a predetermined period of time (for example, 40 seconds) with all the lights of the treatment room turned off, a plurality of background images (for example, For example, after acquiring 40 seconds x sampling rate (n frames/sec), a single background image is generated by collecting and averaging all pixel values in the background image (S2).

In this state, when the dose setting amount is determined from the treatment planning system, etc., and the radiation therapy device starts to irradiate the radiation having the set amount (S3), the camera also starts photographing the plastic fluorescent plate 120 (S4).

After obtaining a dose distribution map by removing background noise included in the captured image through a single background image (S5), the current dose is measured and reported based on the size and color of the visible light generation area in the dose distribution map (S6). ).

In addition, after comparing and analyzing the dose measured amount and the dose setting amount (S7), if the dose measured amount and the dose setting match, re-enter step S3 to continue the radiation treatment, but if not, stop the operation of the radiation therapy device. Or to generate and output an alarm signal to notify the operator of the current state (S8).

As described above, the present invention makes it possible to more simply and accurately measure the dose of a radiation treatment device by using a plastic fluorescent plate that generates visible light corresponding to the amount of radiation transmitted.

On the other hand, as the plastic fluorescent plate is inserted, the dose provided to the patient may be slightly reduced. In particular, the amount of dose reduction may be further increased depending on the thickness of the plastic fluorescent plate.

Accordingly, according to the present invention, the radiation output amount of the radiation therapy device may be corrected as much as the dose reduction amount by inserting the plastic fluorescent plate.

That is, as shown in FIG. 7, the dose reduction amount due to the insertion of the plastic fluorescent plate is inferred based on the deviation between the dose setting amount and the dose measured amount (S11), and reflecting this, the radiation output amount of the radiation therapy device may be corrected. That is, by increasing the radiation output amount of the radiation therapy device 210 as much as the dose reduction amount due to the insertion of the plastic fluorescent plate, the dose finally provided to the patient can be maintained at the initial set value (S12).

Then, the dose change amount is tracked and monitored, and the dose change amount is additionally confirmed to be changed according to the correction amount in step S12 (S13),

As a result of the confirmation in step S13, if the dose change amount does not change according to the correction amount in step S12, it is confirmed and notified that the radiation therapy device cannot adjust the output amount according to the correction amount (that is, the radiation treatment is driven abnormally) (S14). .

The method according to the present invention described above may be produced as a program for execution in a computer and stored in a computer-readable recording medium. Examples of computer-readable recording media include ROM, RAM, CD-ROM, and magnetic tape. , Floppy disks, optical data storage devices, and the like, and also include those implemented in the form of a carrier wave (for example, transmission through the Internet).

The computer-readable recording medium is distributed over a computer system connected through a network, so that computer-readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the method can be easily inferred by programmers in the art to which the present invention pertains.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and the present invention is generally in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications may be implemented by those skilled in the art, and these modifications should not be individually understood from the technical idea or perspective of the present invention.

Claims (8)

1. A plastic fluorescent plate positioned in front of the gantry of the radiation treatment device to transmit the radiation irradiated by the radiation treatment device and to generate visible light corresponding to the amount of radiation transmitted;

   A camera that captures an image of the plastic fluorescent plate to obtain a dose distribution map; And

   A real-time dose monitoring system using a plastic fluorescent plate comprising a processor configured to measure and output a dose based on the size and color of the visible light generation area of the dose distribution map.
2. The method of claim 1,

   Real-time dose monitoring system using a plastic fluorescent plate further comprising a mirror for adjusting the viewing angle of the camera.
3. The method of claim 1, wherein the processor

   A real-time dose monitoring system using a plastic fluorescent plate, characterized in that it further comprises a function of stopping the operation of the radiation therapy device or generating and outputting an alarm signal for operator notification in case of a discrepancy after comparing the dose measured amount with the dose setting value.
4. The method of claim 1, wherein the processor

   Comparing the dose measurement amount with a dose setting value, calculating a dose reduction amount due to the insertion of a plastic fluorescent plate, and calculating a radiation output adjustment amount based on the dose reduction amount, and providing it to the radiation therapy device or treatment planning system. Real-time dose monitoring system using a plastic fluorescent plate characterized by.
5. The method of claim 4, wherein the processor

   If the dose measurement amount does not change according to the radiation output adjustment amount, the system further comprises a function of confirming and notifying the abnormal operation of the radiation therapy device.
6. When the plastic fluorescent plate is positioned in front of the gantry of the radiation treatment device, allowing the radiation treatment device to be driven;

   When the radiation therapy device is driven and visible light corresponding to the amount of radiation transmitted to the plastic fluorescent plate is generated, taking an image of the plastic fluorescent plate to obtain a dose distribution map; And

   Real-time dose monitoring method using a plastic fluorescent plate comprising the step of measuring and notifying the dose based on the size and color of the visible light generation area of the dose distribution map.
7. The method of claim 6,

   After comparing the dose measured amount with the dose setting value, if there is a discrepancy, stopping the operation of the radiation therapy device or generating and outputting an alarm signal for operator notification.
8. The method of claim 6,

   Comparing the dose measurement amount with a dose setting value, calculating a dose reduction amount due to insertion of a plastic fluorescent plate, calculating a radiation output adjustment amount based on the dose reduction amount, and providing it to the radiation therapy device or treatment planning system. Real-time dose monitoring method using a plastic fluorescent plate characterized by.

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