KR20100133240A - Beam-detection method and the detector device for the therapeutic hadron beams - Google Patents

Abstract

PURPOSE: A detecting method, a measuring method thereof, and a device thereof are provided to trace the irradiation location of a hedron beam by simultaneously counting positron annihilation gamma-rays generated by the nuclear interaction. CONSTITUTION: A detector device for therapeutic hadron beam(200) includes a detecting part having the unit detector(215). The unit detector is arranged to be symmetrical to the irradiation location of a beam. The unit detector comprises an optical detecting part(209), an optical sensor(211), and a signal processing part(213). The optical detecting part outputs a first signal by detecting positron annihilation gamma-rays. The optical sensor comprises a 2nX2n channel corresponding to the optical detector. The signal processing part is located between the array where an anger logic is applied and the arranged resistor. The signal processing part comprises an input node connected to the channel of the optical sensor one-to-one.

Description

Detection method and measuring method for therapeutic strong particle beam measurement {Beam-Detection Method and the Detector Device for the Therapeutic Hadron Beams}

The present invention relates to a method and apparatus for measuring a strong particle beam, and more particularly, to a method and an apparatus using the same for measuring a position where the therapeutic strong particle beam is irradiated in the body of the patient.

As a method of treating cancer patients, in addition to drug therapy, radiation treatment, and direct surgery to remove cancer cells, a method of removing cancer cells by irradiating hadrons into the patient's body has been performed. .

About 80% of the energy involved in the strong particle beam is absorbed by ionization energy loss.

Since the strong particle beam has a characteristic of concentrating energy just before being completely absorbed, it is possible to effectively destroy cancer cells while minimizing the exposure of normal cells by controlling the energy of the beam and concentrating the absorbed dose at an appropriate position.

However, unlike gamma rays and x-rays, strong particle beams such as protons and alpha-particle carbon beams have the characteristic of slightly radiating the living body due to nuclear interaction during the beam's progression.

At this time, some of the elements constituting the living body are converted to unstable radioisotopes such as O-15 and C-11 which emit positrons.

Emitted positrons emit two 0.511 MeV gamma rays that vanish with valent electrons in vivo and travel in opposite directions.

The present invention provides a method and apparatus for directly installing in a gantry where strong particle beam treatment is being performed to measure the position where the strong particle beam is being irradiated.

The present invention provides a method and apparatus capable of confirming the irradiation position of a strong particle beam with high resolution.

The present invention provides a method and apparatus for measuring a strong particle beam position with a wide measurement range / effective field of view.

The present invention provides a method and apparatus for determining whether a strong particle beam is irradiated to a treatment site accurately by measuring the irradiation position of the strong particle beam in real time.

The present invention provides a method and apparatus capable of simply measuring the irradiation position of a strong particle beam.

The present invention provides a method and apparatus for real-time tracking of the irradiation position of a strong particle beam during treatment by simultaneously counting positron decaying gamma rays generated by nuclear interaction as the strong particle beam penetrates the patient's living body.

The present invention provides a method and apparatus for securing the safety of the strong particle beam treatment by measuring the irradiation position of the strong particle beam in real time during the strong particle beam treatment.

When describing the preferable form of this invention for solving a subject, it is as follows.

The first aspect includes a detector having a plurality of unit detectors arranged symmetrically with respect to the irradiation position of the strong particle beam,

Unit detector,

A photodetector comprising 3n × 3n (n is an integer of 1 or more) photodetectors for detecting a positron decaying gamma ray and outputting a first signal;

A first signal is input through at least one channel corresponding to the 3n × 3n photodetectors and has a 2n × 2n channel, and the first signal is output. An optical sensor unit for outputting a second signal corresponding to a magnitude;

Positioned between an array of resistors to which Anger logic is applied and the arranged resistors, and having input nodes connected one-to-one to each channel of the optical sensor unit, and outputting a second signal output from the optical sensor unit and a second signal. Receiving an input node connected to the channel of the optical sensor, and comprises a signal processing unit for outputting a third signal passed through the arranged resistance to each output terminal for a therapeutic strong particle beam measuring device.

According to a second aspect, in the first aspect, the therapeutic strong particle beam measuring device further includes an arithmetic processing unit configured to process a signal output from the detection unit, wherein the arithmetic processing unit is configured such that a gamma ray incident on the unit detector is symmetric within a co-efficient time window. When incident to two unit detectors are arranged, the treatment is a strong particle beam measuring device for discriminating by a corresponding gamma ray pair to perform data processing.

The third aspect is the therapeutic strong particle beam measuring apparatus according to the second aspect, wherein the arithmetic processing unit performs data processing when the incident gamma ray falls within a preset energy range.

The fourth aspect is a therapeutic strong particle beam measuring apparatus according to the first aspect or the second aspect, wherein the unit detector is disposed at a position having the same radius around the irradiation position of the strong particle beam.

The fifth aspect is a therapeutic strong particle beam measuring apparatus in which a portion for detecting incident light is disposed in a unit detector at a radius of 40 cm to 60 cm around the irradiation position of the strong particle beam in the fourth aspect. .

In a sixth aspect, in the fourth aspect, the unit detectors are arranged within the azimuth angles in the range of -45 ° to + 45 °, respectively, to the left and right of the object of the strong particle beam such that the unit detector is symmetrical with the irradiation position of the strong particle beam as the origin. It is a therapeutic strong particle beam measuring device.

A seventh aspect is a therapeutic strong particle beam measuring device according to the first or second aspect, wherein the photodetector is a cerium-doped lutetium oxyorthosilicate (LSO) photodetector or a lutetium yttrium oxyorthosilicate (LYSO) photodetector.

The eighth aspect, in the first or second aspect, the unit detector comprises 12 × 12 photodetectors, an optical sensor having 8 × 8 channels, and a signal processor having 8 × 8 input nodes. Particle beam measuring device.

A ninth aspect is the therapeutic strong particle beam measuring device according to the first or second aspect, wherein the pixel area of the photodetector is 4 mm × 4 mm, and each channel area of the optical sensor is 6 mm × 6 mm. .

The tenth form further includes a drive unit in which the therapeutic strong particle beam measuring device is connected to the detection unit in the first or second form, wherein the drive unit moves the detection unit perpendicularly to the plane on which the subject is placed or within the plane on which the subject is placed. It is a therapeutic strong particle beam measuring device to rotate.

The eleventh aspect is the tenth aspect, wherein the drive unit moves the detection unit up to 50 cm vertically with respect to the plane on which the subject is placed.

12th form,

A photodetector having 3n × 3n (n is an integer of 1 or more) photodetectors;

An optical sensor unit having a 2n × 2n channel corresponding to 3n × 3n photodetectors; And

A signal processor having an array of resistors to which Anger logic is applied and having input nodes located between the arranged resistors and connected one-to-one to each channel of the optical sensor unit,

Among the 3n × 3n photodetectors, the photodetector to which the gamma rays are incident outputs a first signal corresponding to the energy of the incident gamma rays,

The optical sensor unit receives the first signal through at least one channel corresponding to the photodetector to which the first signal is output, and outputs a second signal corresponding to the magnitude of the input signal for each channel to which the first signal is input,

The signal processing unit receives the second signal output from the optical sensor unit as an input node connected to a channel for outputting the second signal, and outputs the therapeutic strong particle beam measurement for outputting a third signal through the arranged resistance. For the detector.

The thirteenth form,

Of the photodetectors consisting of 3n × 3n (n is an integer of 1 or more) photodetectors with respect to the irradiation position of the strong particle beam, when positron extinction gamma rays are incident on two symmetric photodetectors, the gamma rays enter through the two photodetectors. Outputting one signal;

The first signal is input through at least one channel corresponding to the photodetector to which the first signal is output using the optical sensor unit of a 2n × 2n channel, and the first signal corresponds to the magnitude of the input signal for each channel to which the first signal is input. Outputting two signals;

Applying a second logic to an input node connected to a channel for outputting a second signal, from among input nodes between the resistors arranged by applying Anger logic, and outputting a third signal through the arranged resistors to each output terminal; And

The therapeutic strong particle beam measuring method includes detecting an incident position of a gamma ray by using a third signal and an angle logic output through an arrayed resistor.

The fourteenth form further includes determining whether the gamma rays incident to the two photodetectors symmetric in the thirteenth aspect are incident within the reference simultaneous counting time window, wherein the detected gamma rays are not incident within the reference simultaneous counting time window. In the case of the determination, the therapeutic strong particle beam measuring method does not output any one of the first to third signals, or processes data on gamma rays as background signal data.

In a fifteenth aspect, in the fourteenth aspect, the outputting step of the first signal is performed by using photodetectors arranged symmetrically in units of 12 × 12, and the outputting step of the second signal is performed using 8 × 8 channels, The output step of the third signal is a therapeutic strong particle beam measuring method performed by using an 8x8 input node corresponding to an 8x8 channel.

In a sixteenth aspect, in the thirteenth or fourteenth aspect, at least the photodetectors are vertically moved with respect to the surface on which the subject of the strong particle beam is placed, or rotated within the surface on which the subject of the strong particle beam is placed, thereby repeatedly performing each step. It is a therapeutic strong particle beam measuring method.

The seventeenth aspect is the therapeutic steel according to the sixteenth aspect, wherein each step is performed at each position during movement while moving at least the photodetector over a total vertical movement distance of 50 cm with respect to the surface on which the subject of the strong particle beam is placed. Particle beam measurement method.

18th form,

Outputting a first signal through a photodetector in which a positron decaying gamma ray is incident from among 3n × 3n photons (n is an integer of 1 or more);

The first signal is input through at least one channel corresponding to the photodetector to which the first signal is output using the optical sensor unit of a 2n × 2n channel, and the first signal corresponds to the magnitude of the input signal for each channel to which the first signal is input. Outputting two signals; And

Among the input nodes between the resistors arranged by applying the Anger logic, receiving the second signal to the input node connected to the channel for outputting the second signal, and outputting the third signal to each output terminal through the arranged resistors It is a detection method for measuring the therapeutic strong particle beam comprising.

A nineteenth aspect has a gamma ray detector including a plurality of unit detectors symmetrically disposed with respect to the irradiation position of the strong particle beam, and the gamma ray detector is moved perpendicular to the plane on which the subject of the strong particle beam is placed or the plane on which the subject is placed. It is a therapeutic strong particle beam measuring device that rotates within.

In a twentieth aspect, the method includes simultaneously counting and detecting gamma rays at both positions symmetrical with respect to the irradiation position of the strong particle beam, calculating a reaction line connecting both positions where the gamma rays are detected, and positron disappearance from the reaction line. A therapeutic strong particle beam measurement method comprising the step of deriving a point.

In a twenty-first aspect, in the twentieth aspect, the therapeutic strong particle beam measuring method is performed by repeatedly performing each step at a position moved vertically from a position where a gamma ray is detected or rotated.

According to the present invention, a device for measuring the position where the strong particle beam is irradiated can be directly installed in the gantry where the strong particle treatment is performed.

According to the present invention, the irradiation position of the strong particle beam can be accurately confirmed with a high resolution of 2 mm level.

According to the present invention, the irradiation position of the strong particle beam can be widely confirmed with a wide measurement range / effective field of view.

According to the present invention, since the irradiation position of the strong particle beam can be measured in real time, the irradiation position of the current strong particle beam can be fed back to the strong particle beam irradiation apparatus so that the strong particle beam can be irradiated at the correct position.

According to the present invention, the irradiation position of the strong particle beam can be measured by a simple method and apparatus.

According to the present invention, the irradiation position of the strong particle beam during treatment can be tracked in real time by simultaneously counting the positron extinction gamma rays generated by nuclear interaction when the strong particle beam penetrates the living body of the patient.

According to the present invention, the safety of the strong particle beam treatment can be secured by measuring the irradiation position of the strong particle beam in real time during the strong particle beam treatment.

When using strong particles, ie, protons or heavy ions, the technology of providing accurate information about the protons or heavy ion beams being irradiated is very important in improving the effectiveness and safety of the treatment.

The strong particle beam used in the treatment produces nuclear beta ⁺ collapsing nuclides with the living body.

The elements constituting the living body contain a lot of ¹² C, ¹⁴ N, and ¹⁶ O. Thus, unstable isotopes that generate β ⁺ decay are produced by nuclear reaction with ¹² C, ¹⁴ N, ¹⁶ O as follows.

¹⁶ O: ¹⁶ O ( p, α ) ¹³ N, ¹⁶ O ( p, p + n + α ) ¹¹ C ¹⁶ O ( p, p + n ) ¹⁵ O

¹⁴ N: ¹⁴ N ( p, p + n ) ¹³ N, ¹⁴ N ( p, 2p + 2n ) ¹¹ C

¹⁴ C: ¹² C ( p, p + n ) ¹¹ C

The half-lives of ¹¹ C, ¹³ N, and ¹⁵ O isotopes by β ⁺ decay are 20.39 minutes, 9.965 minutes, and 122.24 seconds, respectively.

Since water constitutes 70% of the living body, the highest in vivo production probability among these isotopes is ¹¹ C, ¹⁵ O.

The positron produced by β ⁺ decay dissipates along with the valence electron, releasing two 0.511 MeV gamma rays in pairs. The emitted gamma rays are emitted in both directions and symmetrically with respect to the location of the disappearance of the positron and valence electrons.

When treating a patient with a strong particle beam, this gamma ray pair can be counted simultaneously to track the position of the beam in the body in real time.

1 is a graph showing the absorbed dose of the strong particle beam and the position of the Bragg peak according to the depth.

The absorbed dose and Bragg peak for the depth of the irradiated proton beam were measured by using an organic scintillation detector having a density (1.03) almost equal to that of the human body as a phantom.

The ionization energy loss detected through the organic scintillation detector shown in FIG. 1 is computer simulation data representing the absorbed dose occurring in the human body as a function of beam arrival depth during cancer treatment. The position of the Bragg peak to be described.

Particularly in the case of heavy ions, the distribution of positrons generated from nuclear reactions is generally found to be in good agreement with the absorbed dose distribution. By measuring the positron extinction position, it is possible to track the position where the strong particle beam is being irradiated and feed it back to the therapeutic strong particle beam device in real time, thereby increasing the accuracy and stability of the strong particle beam treatment.

Hereinafter, specific embodiments of the present invention will be described with reference to FIGS. 2 to 5. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

2 is a view schematically showing an embodiment of a therapeutic strong particle beam measuring device 200 (hereinafter referred to as "measuring device") according to the present invention.

When the patient 207 to be treated is positioned on the treatment table 225, the strong particle beam irradiation apparatus 201 irradiates the affected particle beam 203 to the affected area to start treatment.

Because strong particle beam therapy irradiates the body with a strong beam of energy, failure to aim the irradiation position accurately will damage other important organs such as nerve cells. Therefore, it is common to start the treatment after accurately checking the position to irradiate the beam in advance.

When the strong particle beam 203 is irradiated into the body, the two gamma rays emitted by positron disappearance are simultaneously counted by the measuring device 200.

The measuring device 200 includes a plurality of unit detectors 215, a shielding device 217, and a calculation processor having a light detector 209, a light sensor 211, and a signal processor 213 mounted with an Anger logic resistor array. 218).

The unit detectors 215 are symmetrically arranged in pairs with respect to the irradiation position of the strong particle beam 203 in the patient's body. This is to detect a pair of gamma rays emitted in opposite directions by the irradiated strong particle beam.

As shown, since the detection of gamma rays is made on the side of the patient so that the strong particle beam 203 can be irradiated freely and accurately, the measuring device 200 is applied to the gantry itself in which treatment is performed through the strong particle beam 203. Equipped with it can increase the accuracy of treatment.

In order to effectively detect the gamma rays emitted, the unit detectors 215 are preferably disposed within azimuth ranges of -45 ° to + 45 °, respectively, on both sides symmetrically with the expected irradiation position of the strong particles as the origin.

In addition, it is preferable that the unit detectors 215 are continuously arranged in order to increase the efficiency of simultaneously counting the two gamma rays.

3 is a view schematically showing an embodiment of a unit detector 215 for the treatment of the therapeutic particle beam according to the present invention.

The unit detectors 215 are arranged in pairs at positions symmetrical with respect to the irradiation position of the strong particle beam, that is, the position where the gamma ray 301 is emitted.

The gamma rays 301 are emitted in pairs in opposite directions, but the directions vary. As shown in FIG. 2, even when the gamma ray 301 is emitted in various directions by arranging the unit detector 215 to form an arc at the same distance around the irradiation position of the strong particle beam 203, the co-efficient of efficiency may be improved.

The unit detector 215 includes a photo detector 209, an optical sensor 211, and a signal processor 213 mounted with an Anger logic resistor array.

The photodetector 209 is composed of 3n × 3n photon detectors (n is an integer of 1 or more). The photodetector 210 may be a device capable of detecting gamma rays, and for example, a microscopic scintillation detector may be used.

In the case of using the microscopic scintillation detector as the photodetector 210, when gamma rays are incident on the microstage scintillation detector, streaks of blue color are generated mainly by Compton scattering or photoelectric effect.

It is advantageous to use an inorganic scintillation crystal detector having a high effective charge and a high density in order to increase the ability to block gamma rays as a fine scintillation detector. Lutium oxyorthosilicate (LSO) or lutetium yttrium oxyorthosilicate (LYSO) is suitable.

In addition, LSO or LYSO has a short decay time, which is advantageous for simultaneously counting high-level radiation, and has an advantage of high amount of flash generation per unit energy and excellent energy resolution.

When the gamma ray is incident, the photodetector 210 outputs a signal corresponding thereto. For example, in the case of using the fine scintillation detector as the photodetector 210, as described above, the scintillation is generated and output as a signal.

The signal output from the photodetector 210 is input to the optical sensor unit 211. The optical sensor unit 211 converts the input signal into an electrical signal and transmits the converted signal to the signal processor 213.

As the optical sensor unit 211, a PhotoMultiplier Tube (PMT) or a Position Sesitive PMT (PSPMT) for amplifying and outputting an input signal into an electrical signal may be used. The use of a photomultiplier tube or a position sensitive photomultiplier tube outputs an amplified electrical signal, so that subsequent data processing can be performed accurately and efficiently.

When the (position sensitive) photomultiplier tube is used as the optical sensor unit 211, the flash generated in the photodetector 210 generates a photoelectric effect at the photocathode of the photomultiplier tube to generate an electronic signal. Electronic signals generated from the photocathode of the optical sensor unit are greatly amplified through a multi-stage dynode array.

The signal processed by the optical sensor unit 211 is input to the signal processor 213 mounted with the resistor array to which the Anger logic is applied.

FIG. 4B illustrates an embodiment of the Anger logic resistor array mounted in the signal processor 213. Details of the signal processor 213 will be described later.

The signal input to the signal processing unit 213 together with the trigger signal is arranged at each output terminal of the signal processing unit as described later, for example, when the signal processing unit as shown in FIG. The electrical signals are output from the four output terminals through the resistors.

The photodetector 209 is composed of 3n × 3n photon detectors (n is an integer greater than or equal to 1). The photodetector 211 is a 2n × 2n channel that receives a signal from the photodetector 209. consist of. For example, when the (position sensitive) photomultiplier tube is used as the optical sensor section 211, the arrangement of the photocathode-diode forms a 2n × 2n channel.

In FIG. 4A, the case where n = 4 is shown for the photodetector 209 consisting of 3n × 3n photodetectors and the optical sensor part 211 of 2n × 2n channel.

In the case where the photodetector 209 is composed of 12 × 12 photodetectors 210 and the optical sensor 211 is composed of 8 × 8 channels, the signal is output from the photodetector 209 (indicated by reference numeral 411). Each of the photodetectors 210 partitioned by the output section and the portion to which a signal is input in the optical sensor section 211 (each channel partitioned by reference numeral 413) correspond as shown.

Looking at the partition 411 consisting of 12 × 12 photodetectors and the partition 413 consisting of 8 × 8 channels, it can be seen that there are three types of correspondences.

In view of the photodetector, among the 144 photodetectors constituting the photodetector 209, contacting only one channel of the optical sensor unit 211 (415), contacting two channels (417), and four channels There is a contact 419. As shown, the number of photodetectors 210 in contact with only one channel of the optical sensor unit 211 is 64, the number of photodetectors 210 in contact with two channels of the optical sensor unit 211 is 64, The number of photodetectors 210 in contact with four channels of the optical sensor unit 211 is sixteen.

The signal output from the photodetector 210 is input to one or more channels of the optical sensor unit 211 which are in contact with each other. The optical sensor unit 211 transfers the received signal to the signal processor 213.

The signal processor 213 includes a resistor array to which Anger logic is applied. An input node corresponding to the channel of the optical sensor unit 211 one-to-one is disposed between the arranged resistors.

FIG. 4B schematically illustrates a resistor arrangement in which an input node 409 corresponding to the optical sensor unit 211 of an 8x8 channel is disposed.

Each of the resistors 401, 403, 405 and 407 is different in size as necessary. The resistors 401 inside the region where the 8x8 input node corresponding to the 8x8 channel of the optical sensor unit 211 are disposed have the same size.

The current signal is input to the input node 409 corresponding to the channel outputting the signal from the optical sensor unit 211 and proceeds in both directions. The current signal is attenuated through the arranged thermal resistance and output through the four output terminals A, B, C, and D.

By applying Anger logic, when the C terminal is set as the reference point (the origin), two-dimensional coordinates (x, y) of the position where the gamma ray is incident can be obtained. If the amount of charges calculated at each terminal is A, B, C, D along the display of the terminal as shown in Fig. 4 (b), the coordinate values x and y are obtained by the following equation (1).

 When applying Anger logic, the way to pass the two-dimensionally arranged resistors is different for all 144 photodetectors, so that their positions are distinct for each photodetector. The number of photodetectors included in one unit detector 215 is 144, but the total number of outputs generated by applying Anger logic is four, and one unit detector including one anode signal used as a trigger is used. A total of 5 output signals are generated and used in.

The arithmetic processing unit 218 is a device configured to process the current signals output from the plurality of unit detectors 215 and the signal processing unit 213 to form data. The operation processor 218 may apply a time window and a threshold value when integrating the current signal and converting the current signal into a value of the charge amount.

The value of the time window is set in consideration of the signal characteristics of the photodetector. For example, when using a micro-flash detector, especially LSO as a photodetector, it is good to integrate a current by applying a time window of 100 ns in consideration of the signal characteristic of LSO.

Nuclear reactions caused by strong particles generate a large amount of background signals caused by various nuclear transfer gamma rays. To minimize accidental simultaneous counting by this background signal, the energy of the incident signal is selected or the time window is adjusted.

For example, the energy selection algorithm is precisely applied to only the signal corresponding to the photoelectric effect of the 511 keV gamma ray corresponding to the quantum extinction, excluding the Compton scattering signal, so as to perform data processing only on the gamma rays belonging to the preset energy range. A large amount of nuclear warfare can be applied to the simultaneous counting of two gamma rays detected from two unit detectors by applying a time window of 50 ns or less to properly exclude the gamma ray coincidence co-efficient.

The operation processing unit 218 processes the above-described data operations, including an analog to digital (AD) converter, a logic circuit (FPGA processor), a data buffer, and the like, and transmits data to the central processing unit 219 through wired Ethernet. The operation processor 218 and the central processor 219 may include a Phy chip, and may be wirelessly connected to each other.

As shown in FIG. 1, the data from the measuring device 200 is processed by the calculation processor 218 and transmitted to the central processing unit 219.

The operation processor 218 may transmit the data obtained at a predetermined time, for example, 1 ms, to the central operation unit 219, or may transmit the data without delay upon detection. A line of response (LOR) passing through the positron disappearance point is formed from the two gamma ray position information thus selected.

The central processing unit 219 calculates the exact position at which the strong particle beam is irradiated based on the received data, and feeds back the strong particle beam irradiation position to the strong particle beam irradiation apparatus 201 in real time. Through this, the position information of the strong particle beam trajectory being irradiated to the patient is grasped in real time, so that the strong particle beam can be irradiated safely at the correct position.

The measuring device 200 may include driving units 221 and 227. The drive unit may include only one of the upper drive shaft 227 and the lower drive shaft 221.

As shown, the upper drive shaft 227 supports and moves the measurement device 200 at the top of the measurement device 200. As shown, the lower drive shaft 221 is connected to the lower portion of the measuring device 200 to support and move the measuring device 200.

By the driving units 221 and 227, the measuring device 200 may move vertically or rotationally.

It is also possible to move only a part of the configuration of the measuring device 200, for example, the position or angle of the photodetector 209, without moving the entire measuring device 200 by the driving units 221 and 227.

As the strong particle beam is irradiated into the body, gamma rays are detected in various directions. Therefore, in order to measure an accurate irradiation position, it is necessary to move the measuring apparatus 200 and scan a wide range.

As shown in FIG. 1, in order to secure a constant effective field of view (detection range) 205, the symmetric measuring device 200 moves up and down while maintaining a constant radius.

For example, if the strong particle beam used is a proton beam of 250 MeV, the inner diameter of the space consisting of the unit detector 215 is maintained at 120 cm to secure an effective field of view 205 having a diameter of 60 cm and a length of 40 cm. For each movement position, gamma ray measurement is performed while moving a total of 50 cm in the vertical direction.

The total measurement time required for one scan while moving the distance is appropriately 10 to 20 seconds.

In addition, the size of the microflash detector and the size of each pixel channel of the light sensor can be appropriately selected to obtain the desired resolution. For example, in order to obtain a 2 mm level resolution for the positron extinction position from the reaction line, the pixel area of the scintillator detector is 4 mm x 4 mm, and the area of the pixel channel of the optical sensor is 6 mm x 6 mm. Can be.

Although detection by vertical movement has been described here, in order to calculate a wide range of data to calculate an accurate irradiation position of the strong particle beam, not only vertical movement but also the measurement apparatus may be rotated so that measurement may be performed at various angles. have.

5 is a flow chart schematically illustrating the method for measuring the treatment of the strong particle beam according to the present invention.

When the treatment with the strong particle beam is started, the measurement is also started at the same time (S501). Nuclear reactions between the strong particle beam and living organisms produce β ⁺ decaying nuclides, and the positrons generated through β ⁺ decay disappear with valence electrons, releasing two 0.511 MeV gamma rays in pairs.

The emitted gamma ray is detected by a photo detector disposed symmetrically with respect to the expected irradiation position of the strong particle beam (S502). The photodetector detecting the gamma ray outputs a signal to the optical sensor unit (S503).

The signal input from the optical sensor unit is output through the signal processor to which the Anger logic is applied (S504). The process of outputting the current signal from the resistor array of the signal processor is as described above.

All signals generated from the signal processor connected to each unit detector are input from the operation processor 218 to select and data two gamma ray signals paired under a co-factor or energy selection condition (S505). Herein, the signal selection is performed by the arithmetic processing unit with respect to the signal that has passed through the signal processing unit. However, the signal selection is performed after the step (S502) of detecting the gamma ray or after each step (S503, S504, S506) where the signal is output. This can be done at any stage.

The data is transmitted to the central processing unit to derive an image constituting the reaction line (S506), and the beam irradiation condition is controlled (S507).

The central processing unit determines whether the strong particle beam irradiation is finished through the monitoring process (S508), and when the irradiation of the strong particle beam is finished, the entire measurement process is terminated (S510).

If the irradiation of the strong particle beam is continued, the detection position is moved (S510), and the measurement is continued.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-described embodiments, and may be implemented in various forms within the scope of the technical idea of the present invention. The above-described embodiments are provided so that this disclosure will be thorough, and will fully inform those skilled in the art to the scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification, the singular forms “a”, “an” and “the” include “comprises” and / or “comprising” unless stated otherwise. Or a device does not exclude the presence or addition of one or more other components, steps, operations and / or devices.

1 is a graph showing the absorbed dose of a strong particle beam with depth as a function of beam arrival depth in vivo.

2 is a view schematically showing an embodiment of a therapeutic strong particle beam measuring apparatus according to the present invention.

3 is a view schematically showing an embodiment of a unit detector for measuring the therapeutic strong particle beam according to the present invention.

FIG. 4A is a diagram schematically illustrating a two-dimensional relationship between a portion of a signal output from a 12 × 12 channel photodetector and a portion of a signal input of an 8 × 8 channel optical sensor.

Figure 4 (b) is a diagram schematically showing the resistance arrangement of the signal processing unit for applying the Anger logic used in the unit detector for the treatment of the strong particle beam for treatment according to the present invention.

5 is a flowchart schematically illustrating a method for measuring a therapeutic strong particle beam according to the present invention.

Claims (21)

A detection unit having a plurality of unit detectors arranged symmetrically with respect to the irradiation position of the strong particle beam, The unit detector, A photodetector comprising 3n × 3n photons (n is an integer of 1 or more) for detecting a positron decaying gamma ray and outputting a first signal; A channel having a 2n × 2n channel corresponding to the 3n × 3n photodetectors and receiving the first signal through at least one channel corresponding to the photodetector to which the first signal is output; An optical sensor unit configured to output a second signal corresponding to the magnitude of the input signal; And A second signal output from the optical sensor unit having an input node located between the array of resistors to which Anger logic is applied and the arranged resistors and connected to each channel of the optical sensor unit one-to-one; Signal processing unit for receiving the input signal connected to the channel of the optical sensor for outputting a signal, and outputs the third signal through the arrayed resistance to each output terminal The therapeutic strong particle beam measuring apparatus comprising a. According to claim 1, The therapeutic strong particle beam measuring device, Further comprising a calculation processing unit for processing the signal output from the detection unit, The calculation processing unit performs a data processing by determining the gamma rays incident on the unit detectors when they are incident on two unit detectors arranged symmetrically within the co-period time window and performing data processing on corresponding gamma rays pairs. Measuring device. The method of claim 2, wherein the operation processing unit, And the data processing is performed when the gamma ray falls within a preset energy range. The method according to claim 1 or 2, wherein the unit detector, The therapeutic strong particle beam measuring apparatus is disposed at a position having the same radius around the irradiation position of the strong particle beam. The method of claim 4, wherein the unit detector, And a portion for detecting incident light is disposed at a radius of 40 cm to 60 cm around an irradiation position of the strong particle beam. The method of claim 4, wherein the unit detector, The therapeutic particle particle beam measuring device for treatment is disposed in the azimuth angle in the range of -45 ° to + 45 °, respectively, to the left and right of the subject of the strong particle beam so as to be symmetrical with the irradiation position of the strong particle beam as the origin.  The method according to claim 1 or 2, wherein the photodetector, A therapeutic strong particle beam measuring device which is a lutetium oxyorthosilicate (LSO) photodetector or a lutetium yttrium oxyorthosilicate (LYSO) photodetector. The method according to claim 1 or 2, The unit detector includes a 12 × 12 photodetector, an optical sensor having an 8 × 8 channel, and a signal processor having an 8 × 8 input node. The method according to claim 1 or 2, The pixel area of the photodetector is 4 mm × 4 mm, And each channel area of the optical sensor is 6 mm × 6 mm. According to claim 1 or claim 2, The therapeutic strong particle beam measuring device, Further comprising a drive unit connected to the detection unit, And the driving unit moves the detection unit perpendicularly to the plane on which the subject of the strong particle beam is placed or rotates in the plane on which the subject is placed. The method of claim 10, wherein the driving unit, The therapeutic strong particle beam measuring apparatus for moving the detection unit vertically up to 50 cm with respect to the plane on which the subject is placed. A photodetector having 3n × 3n (n is an integer of 1 or more) photodetectors; An optical sensor unit having a 2n × 2n channel corresponding to the 3n × 3n photodetectors; And A signal processor having an array of resistors to which Anger logic is applied and having input nodes located between the arranged resistors and connected one-to-one to each channel of the optical sensor unit, Among the 3n × 3n photodetectors, a photodetector to which gamma rays are incident outputs a first signal corresponding to energy of the incident gamma rays, The optical sensor unit receives the first signal through at least one channel corresponding to the photodetector to which the first signal is output, and receives a second signal corresponding to the magnitude of the input signal for each channel to which the first signal is input. Output, The signal processing unit receives the second signal output from the optical sensor unit to an input node connected to the channel for outputting the second signal, and outputs a third signal passing through the arranged resistance. Detector for particle beam measurement. Of the photodetectors consisting of 3n × 3n (n is an integer of 1 or more) photodetectors with respect to the irradiation position of the strong particle beam, when a positron extinction gamma ray is incident on two symmetric photodetectors, the gamma rays enter through the two photodetectors Outputting a first signal; Receiving the first signal through one or more channels corresponding to the photodetector to which the first signal is output by using an optical sensor of a 2n × 2n channel, the size of the input signal for each channel to which the first signal is input Outputting a corresponding second signal; Among the input nodes between the resistors arranged by applying Anger logic, the second signal is input to an input node connected to a channel for outputting the second signal, and the third signal passing through the arranged resistors is output to each output terminal. Making; And Detecting an incident position of a gamma ray by using the third signal and the angle logic output through the arranged resistors Therapeutic strong particle beam measurement method comprising a. The method of claim 13, Determining whether the gamma rays incident to the two symmetric photodetectors are incident within a reference simultaneous counting time window; If it is determined that the detected gamma ray is not incident within the reference simultaneous counting time window, the signal of any one of the first to third signals is not output or the data regarding the gamma ray is processed as background signal data. Therapeutic strong particle beam measurement method. The method of claim 13, The outputting step of the first signal is performed using photodetectors arranged symmetrically in 12 × 12 pieces, The outputting of the second signal is performed using 8 × 8 channels, And outputting the third signal is performed using an 8x8 input node corresponding to the 8x8 channel. The method according to claim 13 or 14, At least the photodetectors are moved vertically with respect to the surface on which the subject of the strong particle beam is placed or rotated within the surface on which the subject of the strong particle beam is placed, thereby repeating each step. The method of claim 16, And performing the respective steps at each position during the movement while moving the at least the photodetector over a total vertical movement distance of 50 cm with respect to the surface on which the subject of the strong particle beam is placed. Outputting a first signal through a photodetector in which a positron decaying gamma ray is incident from 3n × 3n (n is an integer of 1 or more) photodetectors; Receiving the first signal through one or more channels corresponding to the photodetector to which the first signal is output by using an optical sensor of a 2n × 2n channel, the size of the input signal for each channel to which the first signal is input Outputting a corresponding second signal; And Among the input nodes between the resistors arranged by applying Anger logic, the second signal is input to an input node connected to a channel for outputting the second signal, and the third signal passing through the arranged resistors is output to each output terminal. Steps to Detection method for the treatment of the strong particle beam comprising a. It has a gamma ray detector including a plurality of unit detectors symmetrically arranged with respect to the irradiation position of the strong particle beam, And the gamma ray detector is vertically moved relative to the plane on which the subject of the strong particle beam is placed, or rotates within the plane on which the subject is placed. Simultaneously counting and detecting gamma rays at both positions symmetrical to the irradiation position of the strong particle beam; Calculating a reaction line connecting both positions where the gamma ray is detected; And Deriving a positron extinction point from the reaction line Therapeutic strong particle beam measurement method comprising a. 21. The method of claim 20, The method for measuring the strong particle beam for treatment in which the gamma rays are moved vertically from the position at which the gamma rays are detected or are repeatedly executed at the positions at which the gamma rays are rotated.

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