TWI600451B - Particle irradiation treatment device and treatment planning corrective method - Google Patents

Description

Particle beam therapy device and treatment plan correction method

The present invention relates to a particle beam therapy apparatus that treats an affected part such as a tumor by irradiation with a particle beam (particle beam) such as protons or carbon ions, and the particle beam therapy apparatus is used to irradiate a particle beam with a three-dimensional shape of an affected part. The amount of the line is scheduled.

The particle beam therapy system uses a device such as an accelerator to accelerate a charged particle such as a proton or a carbon ion to a million electron volt level of several hundred times, and irradiates it to a patient to provide a linear amount to a tumor in the body, thereby treating cancer. At this time, when the tumor is formed into a linear amount distribution, it is important to be as close as possible to the linear quantity distribution indicated by the physician, that is, the target distribution.

In general, when a particle beam accelerated by an accelerator is irradiated onto an object (including a human body), the three-dimensional line amount distribution in the object has a characteristic of having a maximum peak amount at a certain point. The maximum peak value of this line quantity is called the Bragg peak. Furthermore, when there is a maximum peak amount of the line at one point in the three-dimensional space, the peak position is defined as the "irradiation position" of the particle beam. In order to form a target distribution in a three-dimensional manner using a particle beam having a peak configuration as described above, some technical means are required.

One of the methods for forming a target distribution is a scanning irradiation method. In order to use such a method, it is first necessary to use a biasing mechanism that arbitrarily biases the particle beam in a direction perpendicular to the Z direction belonging to the traveling direction of the particle beam, that is, in the X and Y directions by an electromagnet or the like. . Furthermore, it is necessary to arbitrarily adjust the position at which the Bragg peak is formed in the Z direction by adjusting the particle energy. In general, a particle beam generation and transport device that performs particle beam transport and blockage includes an accelerator that accelerates a particle beam, and the accelerator also has an energy adjustment function. Then, a plurality of irradiation positions (also referred to as spots) are set in the tumor, and the particle beams are sequentially irradiated to the respective irradiation positions by the above two functions. The balance of the amount of the lines given to each of the irradiation positions is adjusted in advance, and the line distribution is given to each of the irradiation positions to form a target distribution.

In the case of the scanning irradiation method, it is possible in principle to form an arbitrary linear quantity distribution for the tumor. However, in most cases, the target distribution within the tumor must be as equal as possible, and the amount of line outside the tumor must be as low as possible within the tumor.

Furthermore, in general particle beam therapy, the amount of thread required for treatment is not irradiated once, and it is often divided into several to several tens of times, and is irradiated repeatedly over a period of one week to two months.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent No. 5555826 (paragraph 0015, Paragraph 0035 to 0040, Figure 3)

Patent Document 2: Japanese Patent No. 4936723 (paragraphs 0008 to 0015)

Non-Patent Document 1: T. Inaniwa, et al., "Development of treatment planning for scanning irradiation at HIMAC", Nuclear Instruments and Methods in Physics Research B 266, 2194-2198 (2008)

Non-Patent Document 2: T. Akagi, et al., "The PTSim and TOPAS Projects, Bringing Geant 4 to the Particle Therapy Clinic", Progress in NUCLEAR SCIENCE and TECHNOLOGY, Vol. 2, pp. 912-917 (2011)

In the scanning irradiation method, when the particle beam is actually irradiated, since there are various uncertain factors, even if the target distribution should be obtained in calculation, the actually obtained line quantity distribution may not become the target distribution. In terms of uncertainties, there are time variations of the beam intensity, temporal changes in the magnetic field of the scanning electromagnet or hysteresis, sensitivity of the line amount monitor, signal delay of the control machine, and noise. Due to these effects, there is a possibility that the actual line quantity distribution becomes different from the calculated value.

An example of a method for compensating for the uncertainty caused by the aforementioned uncertainty factor, for example, when detecting an error in the illumination, considering the excess or deficiency of the amount of the line due to the influence of the error, by the next day Correct the distribution of the amount of illumination line in the future so that the sum of the lines of the number of days The distribution is close to the target line quantity distribution. At this point, it is even more important to accurately and quantitatively estimate the impact of the error produced in the illumination on the line size distribution.

Patent Document 1 describes a method and apparatus for performing patient-specific IMRT verification. The IMRT verification method of Patent Document 1 reconstructs the distribution of the illuminance of the illuminating photon (the number of particles passing through the unit section) corresponding to the beam according to the response of the two-dimensional detector (two-dimensional linear detector). And calculating a three-dimensional line quantity distribution method according to the reconstructed illumination photon flux distribution. However, in the method of calculating the line quantity distribution in Patent Document 1, when the high accuracy and high position resolution of the three-dimensional line quantity calculation are required, the accuracy and position resolution of the two-dimensional detection of the two-position detector must also be improved. However, there are doubts about the development, manufacture, and use of two-dimensional detectors.

Patent Document 2 describes a method and an apparatus for calculating a radiation amount distribution of a radiation therapy system using a limited amount of data. In Patent Document 2, it is determined that the beam quality index of the radiation beam is expressed, and the radiation amount distribution is obtained using a line amount deposition function that is parameterized in accordance with the beam quality index. In this method, the static uncertainty of the calculation of the amount of the line caused by the deviation of each device, the characteristics, the shape of the tumor of the patient, the shape of the irradiation field, and the like can be excluded. However, the method of Patent Document 2 is difficult to compensate for dynamic uncertainties such as temporal changes in the amount of particle beam, delay of the control circuit for changing the current value of the scanning electromagnet, noise, and the like.

Therefore, the object of the present invention is to provide a linear quantity detector without high position resolution, and to accurately and quantitatively estimate static and dynamic The uncertainty of the state imposes an influence on the distribution of the linear quantity, thereby compensating for the two uncertainties.

The particle beam therapy apparatus according to the present invention is a particle beam therapy apparatus that divides a line amount required for particle beam therapy into a plurality of times and applies to an irradiation target, and includes a particle beam generating device that generates energy required for particle beam therapy. a particle beam; the scanning device deflects the particle beam in two directions perpendicular to the direction in which the beam travels, and scans the particle beam at the position where the object is irradiated; the beam transport device transports the particle beam to the scan a measuring device that measures particle beam information of a particle beam generated by a particle beam generating device; a linear amount distribution calculating device that calculates a distribution of an amount of illumination applied to an object to be irradiated by a particle beam, and an amount of illumination line The difference in the distribution of the line quantity between the distribution and the target line quantity distribution; the particle beam information includes the beam amount of the particle beam, the energy, and the position of the beam center axis. The line quantity distribution calculation device includes: a beam information memory unit that memorizes the measured particle beam information measured by the measuring device; and a total line quantity calculation unit that calculates the illumination line quantity distribution according to the measured particle beam information; and the calculation of the line quantity comparison Department, the calculation of the difference in the amount of line calculation; the beam information memory department includes: the measurement energy memory unit, which measures the measured energy obtained by measuring the energy of the particle beam at a plurality of times; the measurement of the central axis of the beam is performed. The position of the central axis of the measurement beam obtained by measuring the position of the central axis of the beam of the particle beam at a plurality of times is memorized; and the measurement of the amount of beam of the beam is measured by measuring the beam amount of the particle beam at a plurality of times. The amount of beam is memorized; the total line amount calculation is performed at all times The inter-section sums the amount of the time interval in which the number of the irradiated particles is multiplied by the unit particle amount, and calculates the line amount of the calculation target point of the irradiation target, wherein the number of the irradiated particles is the same as the time interval in which the particle beam information is measured. Obtaining the measured energy in the interval and measuring the beam amount, the unit particle beam amount being one of the particle beams obtained by measuring the measured energy in the same interval of the time interval and measuring the central axis position of the beam. The amount of the line given by the particle; the particle beam therapy device is controlled in the second and subsequent therapeutic irradiation according to the control data calculated by the treatment planning device and including the corrected beam amount for correcting the difference in the line quantity distribution. .

The particle beam therapy device of the present invention calculates the illumination line quantity distribution and the line quantity distribution difference according to the measurement particle beam information, and the treatment beam after the second and subsequent treatments, according to the correction beam containing the difference of the correction line quantity distribution calculated by the treatment planning device The amount of control data is controlled so that a line detector with high position resolution is not required and both static and dynamic uncertainties can be compensated.

1‧‧‧beam generating device

2‧‧‧beam conveyor

3‧‧‧Scanning device

4‧‧‧x direction scanning electromagnet

5‧‧‧y direction scanning electromagnet

6‧‧‧beam energy measuring device

7‧‧‧Wire measuring device

8‧‧‧beam deflection information measuring device

10‧‧‧Wire quantity distribution calculation device

11‧‧‧Database

12‧‧‧Measured charge memory (measured beam amount memory)

13‧‧‧Measurement beam central axis memory

14‧‧‧Measurement Energy Memory Department

15‧‧ ‧ Total Line Calculation Department

16‧‧‧Development Line Comparison Department

20‧‧‧Particle beam

21‧‧‧Prosthesis

22‧‧‧Treatment planning device

25‧‧ ‧ Total line distribution

26‧‧‧Line distribution

27‧‧‧Line volume distribution

28‧‧‧Line volume distribution

29‧‧‧Line volume distribution

35‧‧‧Measured value memory information

36‧‧‧Database Information

37‧‧‧Measured value information

38‧‧‧ Calculation results information

41‧‧‧Line volume distribution

42‧‧‧Line volume distribution

43‧‧‧Line volume distribution

50‧‧‧Particle ray therapy device

98‧‧‧ Processor

99‧‧‧ memory

Pi‧‧‧Quantity evaluation point (calculation point)

E‧‧‧Energy

E(t)‧‧‧Measure energy

Q, Q(t)‧‧‧Measure the number of charges (measured beam amount)

Px, Py, Px(t), Py(t)‧‧‧Measure beam center axis position

C(E)‧‧‧ scale factor

d _i,k ‧‧‧Line quantity (unit particle amount) or line quantity distribution

w _k ‧‧‧Number of particles (number of irradiated particles)

D _i ‧‧‧ Total line quantity or total line quantity distribution (irradiation line quantity distribution)

△D _i ‧‧‧Distribution of line quantity

D ^obj _i ‧‧‧target line quantity distribution

Q ^c _j ‧‧‧correct total charge number (corrected beam amount)

Q _k ‧‧‧ total charge number

d _z ‧‧‧z direction line quantity (select z-direction line quantity)

d _x ‧‧‧x direction line quantity (select x direction line quantity)

d _y ‧ ‧ _y direction line amount (select y direction line amount)

Line quantity or line quantity distribution in the _{z z} (z, E) ‧ ‧ z direction (z direction line quantity distribution)

dose or dose _{d x (x, z, E} ) ‧‧‧x distribution in the direction (x-direction dose distribution)

d _y (y, z, E) ‧ ‧ y direction line quantity or line quantity distribution (z direction line quantity distribution)

Deflection angle in the direction of θ x‧‧‧x (select the x-direction deflection angle)

Deflection angle in the direction of θ y‧‧‧y (select the y-direction deflection angle)

θ x (B, E) ‧ ‧ x direction deflection angle

θ y (B, E) ‧ ‧ y direction of the deflection angle

Sp1 to sp4‧‧‧ light spots

P1 to p13‧‧‧ line quantity assessment point

Fig. 1 is a schematic configuration diagram of a particle beam therapy system according to a first embodiment of the present invention.

Fig. 2 is a view showing the configuration of the line amount distribution calculation device of Fig. 1.

Fig. 3 is a view showing the hardware configuration of the functional blocks for realizing Fig. 2.

Fig. 4 is a view showing an example of a data structure of the linear amount distribution calculating device input to Fig. 1.

Fig. 5 is a view showing an example of the total line amount distribution and the line amount evaluation point in the particle beam therapy according to the first embodiment of the present invention.

Fig. 6 is a view showing the flow of particle beam therapy according to the first embodiment of the present invention.

Fig. 7 is a view showing the flow of particle beam therapy according to the first embodiment of the present invention.

Fig. 8 is a view showing a modified example of the line amount distribution according to the first embodiment of the present invention.

Embodiment 1.

Fig. 1 is a schematic configuration diagram of a particle beam therapy apparatus according to a first embodiment of the present invention. Fig. 2 is a view showing a configuration of a line amount distribution calculation device of Fig. 1, and Fig. 3 is a view showing a hardware configuration for realizing a function block of Fig. 2. Fig. 4 is a view showing an example of a data structure of the linear amount distribution calculating device input to Fig. 1, and Fig. 5 is a view showing an example of a total line amount distribution and a line amount evaluation point in the particle beam therapy according to the first embodiment of the present invention. Figure. Fig. 6 and Fig. 7 are views showing the flow of the particle beam therapy according to the first embodiment of the present invention. Fig. 8 is a view showing a modified example of the line amount distribution according to the first embodiment of the present invention. In general, the particle beam therapy apparatus 50 that performs particle beam scanning irradiation includes a particle beam generating device 1, a beam transport device 2, and a scanning device 3. The beam generating device 1 is a particle beam 20 that produces the energy required for treatment. The beam transport device 2 is a particle The beam 20 is sent to a particle beam irradiation apparatus including the scanning device 3. In the scanning device 3, the particle beam 20 is oriented in two directions perpendicular to the z direction belonging to the beam traveling direction, that is, in the x direction and the y direction, and the particle beam 20 can be scanned at the patient position.

The scanning device 3 includes the scanning electromagnet 4 in the x direction in which the particle beam 20 is deflected in the x direction, and the scanning electromagnet 5 in the y direction in which the particle beam 20 is deflected in the y direction. The particle beam therapy system 50 includes a control unit (not shown), a line amount measuring device 7, and a position monitor (not shown). The control unit controls the start and stop of the emission of the particle beam 20 by the particle beam generator 1 and the scanning of the particle beam 20 by the scanner device 3. The line amount measuring device 7 measures the line amount of each of the irradiation portions of the treatment target (patient) irradiated by the particle beam 20 scanned by the scanning device 3. The position monitor detects beam information for calculating the passing position (center of gravity position) and size of the beam through which the particle beam 20 scanned by the x-direction scanning electromagnet 4 and the y-direction scanning electromagnet 5 passes. The treatment target (patient) is an object to be irradiated that irradiates the particle beam 20.

In order to eliminate the uncertainties in actually illuminating the particle beam 20, after planning the particle beam therapy plan and before actually irradiating the particle beam 20 to the patient, it is generally carried out with the treatment plan as much as possible Under the same conditions, the phantom (patient substitute) 21 is subjected to particle beam irradiation, and the absolute value (absolute line value) and the line amount distribution of the linear amount are measured, and it is confirmed whether or not the treatment plan is satisfied. This operation is called Patient QA (Quality Assurance). The prosthesis 21 mostly uses water poured into a water tank, and measures the amount of thread using a line amount measuring device provided in water.

When the patient QA is executed, as shown in Fig. 1, the prosthesis 21 is placed at a position where the patient is fixed at the time of treatment. The particle beam therapy apparatus 50 when performing the patient QA includes a particle beam generating device 1, a beam delivery device 2, a scanning device 3, a beam energy measuring device 6, a line amount measuring device 7, a beam deflection information measuring device 8, and The line amount distribution calculation device 10. At the time of treatment, a position monitor (not shown) is disposed between the scanning device 3 and the linear amount measuring device 7, and the patient is fixed at the position of the prosthesis 21. The beam energy measuring device 6 measures the energy of the particles of the particle beam 20. The beam energy measuring device 6 is, for example, a thin film scintillation detector or the like. The line amount measuring device 7 at the time of performing the patient QA and the treatment is, for example, an free cavity, and measures the number of charges (counting value of the unit charge) of the free ions generated by the particle beam 20. The number of charges of the free ions corresponds to the beam amount of the particle beam 20 in a one-to-one correspondence.

The beam deflection information measuring device 8 measures the positions x and y of the beam central axes formed by the x-direction scanning electromagnet 4 and the y-direction scanning electromagnet 5. Specifically, the beam deflection information measuring device 8 performs calculation based on the magnetic field strength B generated by the scanning device 3 on the traveling path of the particle beam 20, and measures the beam central axis position x at a position belonging to the central axis of the beam, y. The beam center axis position x is the position in the x direction, and the beam center axis position y is the position in the y direction. The line amount distribution calculating device 10 measures the number of measured charges measured by the line amount measuring device 7 at a plurality of times in accordance with the measured energy E(t) measured by the beam energy measuring device 6 at a plurality of times, for example, at a predetermined time interval Δt. Q(t) (measurement beam amount), and the measurement beam center axis position measured by the beam deflection information measuring device 8 at a plurality of times Px(t), Py(t), and calculate the line quantity distribution. The energy E of the particle beam 20, the measured beam amount (measured charge number Q), and the measured beam center axis position Px, Py are particle beam information of the particle beam 20. The measured energy E(t), the measured beam amount (measured charge number Q(t)), and the measured beam central axis position Px(t), Py(t) are measured by particle beam information.

The linear amount distribution calculation device 10 includes a data base 11, a measurement charge storage unit 12, a measurement beam central axis storage unit 13, a measurement energy storage unit 14, a total line amount calculation unit 15, and a plan line amount comparison unit 16. The database 11 is stored in the five pieces of information described in the database information 36 of FIG. The measured charge storage unit 12 memorizes the measured charge number Q(t). The measurement beam central axis memory unit 13 memorizes the measurement beam central axis positions Px(t) and Py(t). The measurement energy storage unit 14 memorizes the measured energy E(t). The total line amount calculation unit 15 and the plan line amount comparison unit 16 are realized by the processor 98 executing a program stored in the memory 99. Furthermore, the above functions may be performed by a plurality of processors 98 and a plurality of memories 99 operating in cooperation. The details of the linear amount distribution calculation device 10 will be described later.

First, the total amount of lines given to the tumor volume (tumor area) by scanning irradiation will be described. In the scanning irradiation, a plurality of spots are set in the tumor volume (tumor region), and by irradiating each spot with an appropriate amount of the particle beam 20, for example, the desired total line amount distribution is formed as shown in FIG. 25. The spot number is set to j, the line amount evaluation point number in the prosthesis 21 is set to i, and the line amount given to the i-th line quantity evaluation point pi when the j-th spot is irradiated with one particle is set to d _i,j When the number of particles to the jth spot is set to w _j and the total number of spots is n, the total line amount D _i given to the i-th line amount evaluation point pi when all the spots are irradiated is It can be represented by the formula (1).

In order to make the total line amount D _{i of} the respective line amount evaluation points pi as close as possible to the target line amount distribution (target line amount distribution) D ^obj _i , it is necessary to calculate the number of particles that are optimally given to the light spot w _j before the irradiation. . This step is called a treatment plan. The number of particles w _{j is} appropriately referred to as the number of spot particles w _j .

FIG 5 based on the number and position of the light spot, and one case of w _j of the number of particles for the treatment decision program spot. In the fifth diagram, the vertical axis represents the line amount, and the horizontal axis represents the position in the z direction. In Fig. 5, an example of one of the z-axis (beam traveling direction) directions of the spot arrangement and the line amount distribution is shown for the sake of simplicity. In Fig. 5, four spots sp1, sp2, sp3, sp4, and 13 line quantity evaluation points p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13 are shown. . The line amount distribution 26 is a line amount distribution obtained based on the number of spot particles irradiated to the spot sp1. Similarly, the linear quantity distributions 27, 28, and 29 are linear quantity distributions according to the number of light spot particles irradiated on the light spots sp2, sp3, and sp4, respectively. The total line quantity distribution 25 is a line quantity distribution in which the line quantity distributions 26, 27, 28, and 29 are added together. There are 8 evaluation points for the line quantity evaluation points in the tumor, p3 to p10. There are 5 counts of the line evaluation points p1, p2, p11 to p13 of the line evaluation points outside the tumor.

As shown in Fig. 5, by appropriately determining the number of particles w _j imparted to the spots sp1 to sp4, the total line amount distribution 25 can be made higher in the tumor and lower in the outside of the tumor. In Fig. 5, the number of spots is four, and the number of line evaluation points is 13. However, in general, more spots and line evaluation points are arranged at shorter intervals in accordance with the size of the tumor. Further, in the fifth drawing, the spot arrangement and the line amount distribution are displayed only in one dimension in the z-axis direction for the sake of simplicity, but actually, the spot pattern is arranged so as to include three-dimensional directions in the x-axis direction and the y-axis direction in accordance with the shape of the tumor. In line with the actual tumor shape, the line quantity distribution must also be calculated in three dimensions, so the line quantity evaluation point is also configured in three dimensions.

In general, the position of the light spot in the x direction and the y direction which are perpendicular to the beam traveling direction (z direction) depends on the beam deflection angle, and the beam deflection angle depends on the scanning device 3 The strength of the magnetic field. Furthermore, the position of the spot in the z-axis direction belonging to the direction of travel of the beam depends on and depends on the beam energy of the particle beam 20. Therefore, the particle beam therapy apparatus 50 adjusts the position of the light spot by adjusting the beam energy of the particle beam 20 and the magnetic field intensity of the scanning device 3.

In the formula (1), the total line quantity distribution of the i-th line evaluation point pi is obtained by summing the line quantity distribution of each light spot. For the same object, the line amount distribution after completion of the irradiation of the particle beam 20 can be totaled for each time, and can be calculated in the same manner as in the formula (1) by the formula (2).

Here, the formula (2) is a case where the total irradiation time is divided into m time intervals. k is the number of the time interval. In the i-th line quantity evaluation point pi, the number of particles to be irradiated in the k-th time interval is defined as w _k , and one particle beam is irradiated to the average position of the beam staying in the k-th time interval. The line amount (unit particle ray amount) of the i-th line quantity evaluation point pi is defined as d _i,k . As long as the time interval is sufficiently short, the equation (2) can reproduce the line amount distribution with high accuracy. Here, the time interval is preferably the same as or shorter than the time required for each light spot, and it is preferably, for example, about several tens of microseconds to about 1 millisecond. The number of particles w _{k in the} same time interval is multiplied by the unit particle ray amount d _i,k by w _k d _i,k as the time interval line quantity.

The number of particles w _k irradiated in a certain time interval can be measured, for example, by the line amount measuring device 7 of the free chamber. Generally, a free cavity is a machine that emits an electric signal by passing a particle beam 20, and is connected between the number of particles passing through the particle beam 20 and the number of charges of the emitted free ions (count value of the unit charge). ratio. Accordingly, the total number of charges emitted from the beginning to the end of a certain time interval is Q _k , and the ratio coefficient between the total charge number Q _k and the particle number w _k of the particle beam 20 is C (E). The number of particles w _k can be obtained by the equation (3). The total charge number Q _k represents the beam amount, so the proportional coefficient C(E) can also be referred to as the ratio of the number of particles w _k to the beam amount. Further, the number of particles w _{k is} appropriately referred to as the number of irradiated particles w _k .

[Number 3] Number _{3 w k = C (E)} Q k ‧‧‧ (3)

Here, E is the energy of the particles of the particle beam 20. In general, the proportional coefficient is energy dependent, and the proportional coefficient is an expression of the energy E including the particles in the particle beam 20.

The proportionality factor C(E) must be obtained beforehand for treatment. In one example of the acquisition method, the ratio of the total charge number Q _kr to the number of particles w _kr is known as the reference free cavity, and the therapeutic free cavity actually used during the treatment is obtained by comparing the measured values. The scale factor C(E) is derived. Specifically, the reference free cavity is disposed on the downstream side of the therapeutic free cavity, and by irradiating an appropriate amount of the fixed energy E of the particle beam 20, the number of particles obtained by the output of the therapeutic free cavity w _k and The ratio coefficient C(E) with respect to the energy can be obtained from the ratio of the number of particles w _kr obtained by referring to the output of the free cavity. By performing the same measurement by changing the energy E, the proportionality coefficient (E) with respect to the arbitrary energy E can be known.

It is desirable to measure the total energy E that is likely to be used in the treatment, and to measure the free cavity and the therapeutic free cavity to obtain C(E) and store it as a database. However, in order to omit the measurement procedure, a method of measuring only a plurality of energies E and linearly interpolating the intervals to obtain a function of the proportional coefficient C(E) is also considered. At this point, the approximate accuracy obtained using interpolation must be fully verified and mastered.

The energy E of the particles of the particle beam 20 can be measured by using a beam energy measuring device 6 such as a thin film scintillation detector. Shooting In another example of the beam energy measuring device 6, when there is a curved portion in the path from the particle beam generating device 1 to the patient or the prosthesis 21, it is considered to be used in the beam path. The method of biasing the magnetic field of the electromagnet. Specifically, the beam energy can be obtained from the relationship between the intensity of the magnetic field generated by the electromagnet and the radius of curvature of the beam path, which are arranged on the curved portion of the beam path.

When the line amount evaluation point of the formula (2) is three-dimensional, the line quantity d _i,k can be obtained in the following manner. It is known that the three-dimensional linear quantity distribution d(x, y, z) can be approximated by the product of the linear quantity distribution in the z direction and the linear quantity distribution in the x direction and the linear quantity distribution in the y direction. In the paper by Inaniwa et al. (Non-Patent Document 1), it is introduced that the three-dimensional linear quantity distribution d(x, y, z) with respect to one light beam is factorized into the z direction in the manner of the formula (4). A method of distributing each of the x direction and the y direction.

[Number 4] number 4 d(x, y, z) = d _z (z, E) × d _x (xx ₀ , z, E) × d _y (yy ₀ , z, E) ‧ ‧ (4)

Here, x ₀ and y ₀ are coordinates of the central axis of one beam of depth z. It can be seen from the equation (4) that the linear quantity distribution in the z direction does not depend on the coordinates of the x direction and the coordinates of the y direction, but only depends on the coordinates of the z direction and the beam energy E (the energy E of the beam), but x dose of distribution and y-coordinate system is not only the beam energy and direction of the x coordinate and the y direction, also depending on the position (x _{0, 0} y) coordinates of the beam central axis of the z direction is changed. As described above, in the same object, the line amount distribution after the end of the irradiation of the particle beam 20 is equal to the case where the line amount distribution of each spot is totaled, and can be totaled for each time, so the line amount evaluation point is three-dimensional. The linear amount d _{i,k of the case} is factorized into the linear quantities of each of the z direction and the x direction and the y direction, and can be expressed by the formula (5).

[Number 5] number 5 d _i,k =d _z (z,E)×d _x (x,z,E)×d _y (y,z,E)‧‧‧(5)

Further, d _{z (z,} E) system relative to an arbitrary z coordinate curve of the z-direction of the profile, but with respect to the unique z coordinate in terms of the value of dose of the their z coordinate, it is based on z coordinates of the sole or any Instead, use a line quantity distribution or line quantity. The same is true for d _x (x, z, E) and d _y (y, z, E), and the linear distribution of the x direction and the linear distribution of the y direction with respect to arbitrary (x, y) coordinates, respectively. The unique (x,y) coordinate is the value of the line quantity of the (x,y) coordinate, so the line quantity distribution or line quantity is used depending on whether the (x,y) coordinate is unique or arbitrary. The i-th linear quantity evaluation point pi is due to its coordinate (x, y, z) being the sole determinant, so d _z (z, E), d _x (x, z, E), d _y (y, z, E The lines are the amount of lines in the z direction, the amount of lines in the x direction, and the amount of lines in the y direction. When considering an arbitrary i-th line quantity evaluation point pi, it is expressed as a line quantity distribution in each direction. Furthermore, similarly, for D _i , d _{i , k , the} line quantity distribution or the line quantity is also distinguished according to whether the line quantity evaluation point is unique or arbitrary. When used for the unique line quantity evaluation point, it is expressed as the total line quantity D _i and the line quantity d _i,k , and when used for any line quantity evaluation point, it is expressed as the total line quantity distribution D _i and the line quantity distribution d _i,k .

The position of the central axis of the beam of the formula (4) can also be obtained by analytical calculation based on the Lorentz force expressed by the formula (6).

[Number 6] number 6 f=qvB‧‧‧(6)

Here, the q, v, and B systems of the formula (6) are the charge of the particles, the velocity of the particles, and the magnetic flux density of the magnetic field imparted to the particles. In addition, only the description of the formula (6) and the Lorentz force will describe B as the magnetic flux density.

The position of the central axis of the beam can also be directly measured and databaseed beforehand. That is, as long as the position monitor is provided on the downstream side of the scanning device 3, and a magnetic field of a certain magnetic field strength B is generated, the particle beam 20 is irradiated in a certain beam energy E, and the position at which the beam central axis passes is measured. The deflection angle θ of the particle beam 20 can be known from the arrangement distance of the scanning device 3 and the position monitor. The x coordinate and the y coordinate based on the beam center axis at an arbitrary position z (z coordinate) can be calculated from the deflection angle of the beam. The measurement of the deflection angle θ of the beam is also preferably performed in advance for all of the beam energy E and the magnetic field strength B that are likely to be used in the treatment, but in order to omit the procedure, several data may be obtained. Use linear interpolation afterwards. In particular, regarding the magnetic field strength B, it is expected that there is a linear relationship between the magnetic field strength B and the deflection angle θ according to the definition of the Lorentz force. Therefore, even if a certain degree of measurement is omitted and interpolation is performed, accuracy may not be expected. reduce. Further, the deflection angle θ in the x direction is denoted by θ _x , and the deflection angle θ in the y direction is denoted as θ y . Further, since the deflection angle θ depends on the magnetic field strength B and the position z (z coordinate), the deflection angle θ _x is appropriately labeled as θ _x (B, E), and the deflection angle θ _{y is} marked as θ _y (B, E). ).

The linear quantity distribution d _z (z, E) in the z direction of the equations (4) and (5) can be calculated by the known theory of the Bragg formula, but it is considered that the water prosthesis (prosthesis) is used beforehand. 21) and the line gauge is actually measured and databaseed, which is the easiest method. When the measurement is performed in advance, the water is injected into the water prosthesis, and the astigmatometer is placed, and the particle beam 20 is irradiated while moving the position of the line gauge in the z direction, thereby obtaining the distribution. If the measurement for obtaining the proportional coefficient C(E) is performed before the measurement is performed, the number of irradiated particles w and the amount of line d in the water prosthesis can be obtained by arranging the current therapeutic free cavity upstream. . Further, by obtaining the ratio, the linear amount distribution d _z (z, E) with respect to one particle can be known.

Dose of formula (4) The distribution of d _x dose (xx _0, z, E) and (5) the distribution of _{d x (x, z, E} ), based can be based on Moliere, Fermi-Eyges, Highland et al.'S Multiple scattering theory to calculate. Furthermore, it is also possible to actually measure the water prosthesis (prosthesis 21) and the linear meter beforehand and store the data. This measurement is compared to the measurement of the linear quantity distribution d _z (z, E). Since the linear quantity distribution varies depending on both x and z, measurement must be performed for all x and z, but it takes considerable effort. Therefore, by using a known Monte Carlo simulation tool such as Geant4 (Non-Patent Document 2), the amount of each particle at any position in the water prosthesis (prosthesis 21) can be calculated. Specifically, when the Monte Carlo simulation is performed, the shape of the object such as the prosthesis 21, the energy of the particle beam 20, the free generation position, the generation direction, and the electromagnet of the scanning device 3 (x) By scanning the electromagnet 4, scanning the electromagnet 5 in the y direction, and deflecting the position of the central axis of the beam, it is possible to calculate the linear amount of each particle at any position in the water prosthesis (prosthesis 21). Therefore, as long as the Monte Carlo simulation is performed, the linear quantity distribution d _x (xx ₀ , z, E), the linear quantity distribution d _x (x, z, E), and the like in the x direction can be obtained more efficiently than the actual measurement. Regarding the linear quantity distribution in the y direction, that is, the linear quantity distribution d _y (yy ₀ , z, E) of the formula (4) and the linear quantity distribution d _y (y, z, E) of the formula (5) are also the same.

When using the Monte Carlo simulation tool, not only the linear quantity distribution in the one-dimensional direction, but also the three-dimensional direction linear quantity distribution d(x, y, z) can be directly calculated, and can be calculated beforehand and d(x, y , z) The method of holding information as a database. However, since it is necessary to store a large amount of memory capacity in a memory device system, it is necessary to consider the performance of the memory device and the required data accuracy, and to review the form in which the data is to be maintained.

The flow of the particle beam treatment of the present invention will be described using Figs. 6 and 7. In Fig. 6, the database information 36 prepared before the particle beam treatment is recorded from top to bottom in time series, and the measured value information 37 measured in each beam irradiation divided in the particle beam therapy, and The calculation result information 38 after the beam irradiation calculation. In Fig. 7, a flow chart showing the particle beam treatment divided into a plurality of times is shown. First of all, before the start of the irradiation (at the start of the facility, etc.), in order to obtain the required information by the method described above, the information of the five information recorded in the database information 36 is created. The operation of the library 11 (database creation steps). The first database converts the measured charge number Q(t) belonging to the number of output charges of the linear quantity measuring device 7 into a coefficient of the number of particles w, that is, a proportional coefficient C(E). The second database is the linear quantity distribution d _z (z, E) in the z direction. The third database is the x-direction line quantity distribution d _x (x, z, E). The fourth database is the y-direction line quantity distribution d _y (y, z, E). The fifth database is the magnetic field intensity B formed by the electromagnet (the x-direction scanning electromagnet 4 and the y-direction scanning electromagnet 5) of the scanning device 3 and the deflection angle θ _x (B, E), θ of the particle beam 20 . Conversion table for _y (B, E).

Next, when the patient is actually treated, CT photography is first performed to find the position and shape of the tumor, and then the treatment plan device 22 performs the planning of the treatment plan (the treatment plan preparation step). And a flow of irradiating the particle beam 20 to the patient (the treatment irradiation step) according to the treatment plan is performed. In addition, during the period from the planning of the treatment plan to the irradiation of the patient, the patient QA operation (patient QA step) must be performed at a certain time. Patient QA is generally considered to be performed mostly one day before the irradiation of the patient, but is not limited thereto.

In the beam irradiation of the particle beam therapy, the measured charge number Q and the measurement beam central axis position Px, Py belonging to the three measured values described in the measured value information 37 are measured for each predetermined time interval Δt. And energy E (therapeutic data measurement step). The measured charge number Q (measured beam amount) is all the data of the measured charge number Q(t) (information for measuring the beam amount) belonging to the number of charges of the line amount measuring device 7 measured per time interval Δt. The measurement beam central axis positions Px and Py are measurement beam center axis positions Px of the magnetic fields of the x-direction scanning electromagnet 4 and the y-direction scanning electromagnet 5 of the scanning electromagnet 3 measured for each time interval Δt. ), Py(t) full information. The energy E is the total amount of the measured energy E(t) of the beam energy belonging to the particle beam 20 measured per time interval Δt.

The measured charge number Q, the measured beam central axis position Px, Py, and the energy E are respectively stored in the measured charge storage unit 12, and the measurement beam The central axis memory unit 13 and the measurement energy storage unit 14. The measured charge number Q is also referred to as the measured beam amount, so the measured charge memory portion may also be referred to as a measured beam amount memory portion. The measured charge number Q, the measured beam center axis positions Px, Py, and the energy E can be aggregated into a data structure of the measured value memory information 35 as shown in FIG. At time t1 representing the first measurement section, the measured charge number Q(t1), the measured energy E(t1), and the measured beam central axis position Px(t1), Py(t1) are measured. At time t2 when the time interval Δt elapses, the measured charge number Q(t2), the measured energy E(t2), and the measured beam central axis position Px(t2), Py(t2) are measured. The measured charge number Q(t), the measured energy E(t), and the measured beam central axis position Px(t), Py(t) are measured in the same manner each time the time interval Δt elapses. At the time tn representing the last measurement interval, the measured charge number Q(tn), the measured energy E(tn), the measured beam central axis position Px(tn), Py(tn) are measured. Further, the measurement charge storage unit 12, the measurement beam central axis storage unit 13, and the measurement energy storage unit 14 may be external storage areas of the memory area of the non-linear amount distribution calculation device 10.

After the irradiation, information (measured charge number Q, measured beam center axis position Px, Py, energy E) stored in the measured charge storage unit 12, the measured beam central axis position memory unit 13, and the measured energy storage unit 14 is measured. And the information of the database 11, the linear quantity distribution calculation device 10 calculates the total line amount distribution D _i in the body of the patient (total line amount distribution calculation step). In the total line quantity distribution calculation step, the three irradiation particle numbers w _k , the line quantity distributions d _{i, k} , and the total line quantity distribution D _i described in the calculation result information 38 are calculated. The total line amount calculation unit 15 calculates the number of irradiation particles w _k from the proportional coefficient C(E) and the measured charge number Q(t) corresponding to the total number of charges Q _{k for} each measurement section by the equation (3). Further, the total line amount calculation unit 15 is based on the z-direction line quantity distribution d _z (z, E) selected by measuring the beam center axis positions Px, Py, and energy E, and the x-direction line quantity distribution d _x (x, z, E), y direction line quantity distribution d _y (y, z, E), the line quantity distribution d _{i,k is} calculated by the formula (5).

In addition, the linear quantity distribution calculation device 10 compares the calculated total line quantity distribution D _i with the target line quantity distribution D ^obj _i per day by the plan line quantity comparison unit 16 , and calculates the difference in the line quantity distribution by the equation (7). ΔD _I (Line amount distribution difference calculation step).

In the linear quantity distribution difference calculation step, the linear quantity distribution calculation device 10 calculates the linear quantity distribution difference ΔD _i described in the calculation result information 38. Further, the linear amount distribution calculating device 10 transmits the linear amount distribution difference ΔD _i to the treatment planning device 22. The treatment planning device 22 plans the next day's treatment plan (the treatment plan correction step) in such a manner as to correct the line amount distribution difference ΔD _i . That is, the corrected spot particle number w ^c _{j is} calculated in such a manner as to satisfy the formula (8).

In the next day of therapeutic irradiation, the particle beam therapy apparatus 50 irradiates the particle beam 20 based on the corrected spot particle number w ^c _j . As a result, as shown in Fig. 8, the particle beam therapy system 50 is capable of making the total irradiation line amount distribution (total line amount distribution 43) of two days equal to the target line amount distribution of two days. In the eighth diagram, the vertical axis represents the line amount, and the horizontal axis represents the position in the x direction. The linear amount distribution 41 is a linear quantity distribution in the x direction generated by the beam irradiation in the treatment on the first day, and the linear quantity distribution 42 is a linear quantity distribution in the x direction generated by the beam irradiation in the treatment on the second day. The total line amount distribution 43 is a line amount distribution in the x direction in total for two days.

The flow of the particle beam therapy of the first embodiment described above will be described using Fig. 7 . In step S001, the treatment planning device 22 calculates the total number of charges Q _j (number of particles w _j ) for each spot based on the target line amount distribution D ^obj _i per day (the treatment plan preparation step). In step S002, the particle beam therapy device 50 irradiates the patient with the particle beam 20 according to the total charge number Q _j (number of particles w _j ) of each spot determined by the treatment plan of the treatment planning step (primary irradiation step) ). In step S003, the linear quantity distribution calculation device 10 calculates the total line amount distribution D _i and the line amount distribution difference ΔD _i (the line amount distribution calculation step). The line quantity distribution calculation step is a step of performing the above-mentioned total line quantity distribution calculation step and the line quantity distribution difference calculation step.

In step S004, the treatment planning device 22 calculates the corrected total charge number Q ^c _j (the corrected spot particle number w ^c _j ) for each spot based on the line amount distribution difference ΔD _i (the treatment plan correction step). In step S005, the particle beam therapy device 50 irradiates the patient with the particle beam 20 based on the corrected total charge number Q ^c _j (the corrected spot particle number w ^c _j ) for the spot determined by the treatment plan creation step. In step S006, steps S003 to S005 are repeatedly performed until the number of treatments determined by the treatment plan is reached.

Here, the calculation operation of the total line amount calculation unit 15 will be described in detail. Total dose calculation unit 15 reads from the database system 11 to scale the coefficient of energy E C (E), and the number of measuring charge Q (t) and the proportionality coefficient C (E) by multiplying the number of particles irradiated calculating w _k. Furthermore, the calculation of the line quantity distribution d _i,k of the total line quantity calculation unit 15 will be described by taking the ith line quantity evaluation point pi as an example. The total line amount calculation unit 15 derives the z coordinate belonging to the i-th line quantity evaluation point pi from the z-direction line quantity distribution d _z (z, E) of the database 11 and is a line amount in accordance with the z direction of the energy E, that is, the z direction is selected. Line quantity d _z .

The total line amount calculation unit 15 derives the x-direction deflection angle corresponding to the measurement beam center axis positions Px and Py and the energy E from the beam deflection angles θ _x (B, E) and θ _y (B, E) of the database 11 ( Select the x-direction deflection angle) θ _x and the y-direction deflection angle (select the y-direction deflection angle) θ _y . The total line amount calculation unit 15 calculates the x coordinate from the deflection angle θ _x in the x direction, and derives the z coordinate corresponding to the x coordinate and the line quantity evaluation point from the x direction line quantity distribution d _x (x, z, E) of the database 11 and The amount of line in the x direction of energy E (select the amount of x direction line) d _x . Similarly, the total line amount calculation unit 15 calculates the y coordinate from the deflection angle θ _y in the y direction, and derives the y coordinate and the line quantity evaluation point from the y direction line quantity distribution d _y (y, z, E) of the database 11 . The z-coordinate and the amount of line in the y direction of the energy E (select the amount of y-direction line) d _y .

Relative to the total amount calculating unit 15 based according to the z-direction derived from the dose D _z, dose d _{x x} direction, dose d _{y y} direction, three dose d _z, d _x, d _y is multiplied by the formula (5) To calculate d _{i,k by this} . The total line amount calculation unit 15 calculates the line amount d _i,k for each line amount evaluation point and time interval, and obtains the line quantity distribution d _i,k . W _k the number of particles and the total irradiation dose based system 15 has dose calculation unit calculating a distribution of d _{i, k,} by the formula (2) the total calculated dose distribution D _i.

The linear amount distribution calculation device 10 of the first embodiment calculates the distribution of the irradiation dose amount given to the patient based on the measured particle beam information (energy E, the measured beam amount (measured charge number Q), and the measured beam central axis position Px, Py) ( total dose distribution D _i), and compare the irradiation amount distribution (total dose distribution D _i) D ^obj _i and dose target 1 should be distributed, calculated belongs irradiation amount distribution (total dose distribution D _i) and the target dose distribution D ^obj differences in dose distribution difference _i △ D _i, and therefore need not have a high resolution position detector dose, and may be accurately and quantitatively estimate the effect of both the static and dynamic uncertainty of the cause of the dose distribution. The particle beam therapy apparatus 50 according to the first embodiment is a modified total number of charges Q ^c _j (corrected number of spot particles w ^c ₎ calculated by the treatment planning device 22 based on the linear amount distribution difference ΔD _i at the time of the second and subsequent treatment irradiations. _j) irradiating the particle beam 20 patients, there is no need of having a high resolution position detector dose, and may be both static and dynamic compensation of the uncertainties.

In the particle amount distribution calculation device 10 of the first embodiment, when the particle beam therapy device 50 performs the particle beam therapy on the irradiation target scanning particle beam 20 by the scanning device 3, the particle beam irradiation device 50 is provided with the irradiation line amount distribution to be irradiated ( total dose distribution D _i) and the irradiation amount distribution (total dose distribution D _i) belonging to the target dose distribution of the dose differences D ^obj _i distributional difference △ D _i by, the dose distribution calculating means 10 based comprising: a beam information storage unit (Measurement energy storage unit 14, measurement beam amount storage unit (measurement charge storage unit 12), measurement beam central axis storage unit 13), memory measurement device (beam energy measurement device 6, linear amount measurement device 7, shot) The beam deflection information measuring device 8) measures the particle beam information of the particle beam information belonging to the particle beam 20; the total line amount calculation unit 15 is based on measuring the particle beam information (energy E, measuring beam amount (measurement) The charge number Q), the measurement beam central axis position Px, Py), the calculation of the irradiation line quantity distribution, and the plan line quantity comparison unit 16 are calculated to belong to the illumination line quantity distribution (total line quantity distribution D) _i ) The difference in the amount distribution of the difference from the target line quantity distribution D ^obj _i ΔD _i . According to the linear quantity distribution calculation device 10 of the first embodiment, the illumination line quantity distribution (the total line quantity distribution D _i ) and the line quantity distribution difference ΔD _{i are} calculated based on the measured particle beam information, so that the line quantity detection with high position resolution is not required. The correct and quantitative estimate of the effects of both static and dynamic uncertainties on the linear distribution.

Further, the particle beam information of the linear amount distribution computing device 10 of the first embodiment includes the beam amount, energy, and beam central axis position of the particle beam 20, and the beam information memory unit includes a measurement energy storage unit 14. The measurement energy E(t) obtained by measuring the energy of the particle beam 20 at a plurality of times is memorized; the measurement beam central axis memory portion 13 measures the beam central axis position of the particle beam 20 at a plurality of times. The measured beam center axis positions Px(t), Py(t) are memorized; and the measured beam amount memory portion (measured charge memory portion 12) is used to measure the beam amount of the particle beam 20 at a plurality of times. The resulting measured beam amount (measured charge number Q(t)) is memorized. The total line amount calculation unit 15 of the linear quantity distribution calculation device 10 of the first embodiment adds up the time interval amount by multiplying the number of irradiation particles w _k by the unit particle beam amount (line amount d _i,k ) in all time intervals. And calculating the line amount of the calculation target point (line quantity evaluation point pi) of the irradiation target, wherein the number of the irradiation particles is the measurement energy E(t) and the measurement beam in the same interval of the time interval in which the particle beam information is measured. The amount of the unit particle ray is determined based on the measured energy E(t) in the same interval of the time interval and the measured beam center axis positions Px(t), Py (the amount of charge Q(t)) is obtained. t) The amount of line given by one of the particle beams 20 is determined. The program line amount comparison unit 16 of the linear quantity distribution calculation device 10 according to the first embodiment calculates the linear quantity distribution difference ^ΔD _i belonging to the difference between the irradiation line quantity distribution (the total line quantity distribution D _i ) and the target line quantity distribution D ^obj _i . According to the linear quantity distribution calculation device 10 of the first embodiment, the total line amount calculation unit 15 measures the energy E(t) of each time interval, the measurement beam center axis positions Px(t), Py(t), and Measuring the beam amount (measuring the charge number Q(t)), calculating the illumination line quantity distribution (total line quantity distribution D _i ) and the line quantity distribution difference ΔD _i , thus eliminating the need for a line amount detector with high position resolution, which can be correctly and quantitatively Estimate the impact of both static and dynamic uncertainties on the distribution of linear quantities.

The particle beam therapy apparatus 50 according to the first embodiment is configured to divide a line amount required for particle beam therapy into a plurality of times, and to provide an object to be irradiated. The particle beam therapy apparatus includes a particle beam generating apparatus 1 for generating a particle beam therapy facility. a particle beam 20 of energy required; the scanning device 3 deflects the particle beam 20 in two directions perpendicular to the direction in which the beam travels, and scans the particle beam 20 at an arrangement position of the irradiation target; the beam delivery device 2 The particle beam 20 is sent to the scanning device 3; the measuring device (the beam energy measuring device 6, the beam deflecting information measuring device 8, and the beam amount measuring device (the line measuring device 7)) measure the particle beam generation The particle beam information of the particle beam 20 generated by the device 1 and the linear quantity distribution calculation device 10 calculate the distribution of the illumination line amount (total line quantity distribution D _i ) and the irradiation line quantity distribution which are given to the irradiation target by the particle beam 20 (total dose distribution D _i) of the difference in dose distribution D ^obj _i the difference △ D _i to the target dose distribution; particle beam therapy system 50 in the treatment after the irradiation of the second time, according to the rule Program means 22 comprises calculating the dose distribution difference △ D _i be the amount of correction of the correction beam (corrected total charge Q ^c _j) of the control data and controls. The linear amount distribution calculation device 10 of the particle beam therapy system 50 according to the first embodiment includes a beam information storage unit (measurement energy storage unit 14, measurement beam amount storage unit (measurement charge storage unit 12), and measurement beam central axis memory). The part 13) memorizes the measured particle beam information measured by the measuring device (the beam energy measuring device 6, the line amount measuring device 7, and the beam deflecting information measuring device 8); the total line amount calculating unit 15 is based on the measured particle beam Beam information (energy E, measured beam amount (measured charge number Q), measured beam center axis position Px, Py), calculated irradiation line quantity distribution (total line quantity distribution D _i ); and planned line quantity comparing unit 16 is calculated The line quantity distribution difference ΔD _i . According to the particle beam therapy apparatus 50 of the first embodiment, the particle beam information (energy E, the measured beam amount (measured charge number Q), the measured beam center axis position Px, Py) is measured by the characteristics, and the irradiation is calculated. The line quantity distribution (total line quantity distribution D _i ) and the line quantity distribution difference ΔD _i , and in the second and subsequent treatment irradiations, according to the correction calculated by the treatment planning device 22 including the correction of the line quantity distribution difference ΔD _i The control data of the beam amount (corrected total charge number Q ^c _j ) is controlled, so that a line amount detector with high position resolution is not required, and both static and dynamic uncertainties can be compensated.

The treatment plan correction method according to the first embodiment is a modified particle beam therapy program that divides the amount of wire required for particle beam therapy into a plurality of times and provides treatment to the irradiation target by the particle beam therapy device 50. plan. The treatment plan correction method includes the following steps: a treatment data measurement step of measuring particle beam information (energy, beam amount, beam center axis) of the particle beam 20 generated by the particle beam therapy device 50 at a plurality of times. And collecting and measuring particle beam information (energy E, measuring beam amount (measuring charge number Q), measuring beam central axis position Px, Py); total line quantity distribution calculation step is measured according to measuring particle beam information The particle beam information (energy E, the measured beam amount (measured charge number Q), the measured beam center axis position Px, Py) is measured for each time interval, and the distribution of the illumination line amount given to the irradiated object by the particle beam 20 is calculated. (Total line quantity distribution D _i ); the line quantity distribution difference calculation step is to calculate the line quantity distribution difference ^ΔD _i of the difference between the irradiation line quantity distribution (total line quantity distribution D _i ) and the target line quantity distribution D ^obj _i ; and the treatment plan correction step , the dose distribution calculation based difference △ D _i be the amount of correction of the correction beam (corrected total charge Q ^c _j). The treatment plan correction method according to the first embodiment is based on measuring particle beam information (energy E, measuring beam amount (measured charge number Q), measuring beam central axis position Px, Py), and calculating the irradiation line quantity distribution (total line quantity distribution) D _i ) and the difference in the amount distribution ΔD _i , and the difference in the amount distribution ΔD _{i is} transmitted to the particle beam therapy device 50, so in the second and subsequent treatment irradiation, according to the calculation by the treatment planning device 22 The particle beam therapy device 50 is controlled by controlling the particle beam therapy device 50 including control data for correcting the beam amount (corrected total charge number Q ^c _j ) for correcting the line amount distribution difference ΔD _i , thereby eliminating the need for a line amount detector having high position resolution, and compensating for static And dynamic uncertainty.

Further, the present invention is described by taking three examples of the simultaneous use energy E, the measured beam amount (measured charge amount Q), and the measured beam central axis position Px, Py as measured particle beam information measured by the measuring device. , but only one can be used. As described above, in the method of calculating the line amount distribution of Patent Document 1, a two-dimensional line amount detector in which the accuracy of two-dimensional line quantity detection and the position resolution are both high is required. On the other hand, in the present invention, if the measurement beam amount (measured charge number Q) is set as the measurement particle beam information, a line amount detector having high position resolution is not required, and static and dynamic uncertainties can be compensated for. Both of sex. Further, the present invention can be combined with various configurations within the scope of the invention, or modified as appropriate, and the respective configurations are omitted.

1‧‧‧beam generating device

2‧‧‧beam conveyor

3‧‧‧Scanning device

4‧‧‧x direction scanning electromagnet

5‧‧‧y direction scanning electromagnet

6‧‧‧beam energy measuring device

7‧‧‧beam measuring device

8‧‧‧beam deflection information measuring device

10‧‧‧Wire quantity distribution calculation device

20‧‧‧Database

21‧‧‧Prosthesis

22‧‧‧Treatment planning device

50‧‧‧Particle ray therapy device

E(t)‧‧‧Measure energy

Px(t), Py(t)‧‧‧measuring beam center axis position

Q(t)‧‧‧Measured charge number

△D _i ‧‧‧Distribution of line quantity

Claims (4)

A particle beam therapy apparatus for dividing an amount of a line required for particle beam therapy into a plurality of times to be given to an object to be irradiated, the particle beam therapy apparatus comprising: a particle beam generating device for generating energy required for particle beam therapy a particle beam; the scanning device deflects the particle beam in two directions perpendicular to a direction in which the beam travels, and scans the particle beam at an arrangement position of the irradiation target; and the beam transport device emits the particle The beam is transported to the scanning device; the measuring device measures the particle beam information of the particle beam generated by the particle beam generating device; and the linear amount distribution calculating device is calculated by the particle beam to impart the aforementioned irradiation The illumination line quantity distribution of the object and the difference in the line quantity distribution belonging to the difference between the illumination line quantity distribution and the target line quantity distribution; the particle beam information includes the beam amount, the energy, and the beam central axis position of the particle beam; the aforementioned line quantity distribution calculation The device system includes: a beam information memory unit, and the memory is measured by the foregoing measuring device The measurement of the particle beam information; the total line amount calculation unit calculates the radiation line quantity distribution based on the measured particle beam information; and the plan line quantity comparison unit calculates the difference of the line quantity distribution; the beam information memory part includes: The measuring energy memory unit memorizes the measured energy obtained by measuring the energy of the particle beam at a plurality of times; measuring the central axis of the beam, and measuring the central axis of the beam Position, the measurement beam center axis position is obtained by measuring the beam center axis position of the particle beam according to the deflection information of the beam deflected by the scanning device at a plurality of times; and measuring the beam amount memory portion, The measured beam amount obtained by measuring the beam amount of the particle beam at a plurality of times is memorized; the total line amount calculation unit multiplies the number of irradiated particles by the unit particle beam amount in all time intervals. The interval line quantity is added to calculate the line amount of the calculation target point of the irradiation target, wherein the number of the irradiation particles is the aforementioned measurement energy and the aforementioned measurement beam amount in the same section of the time interval in which the particle beam information is measured. And the unit particle beam amount is a line amount given by one of the particle beams obtained based on the measured energy in the same interval of the time interval and the position of the measurement beam central axis; The particle beam therapy device is based on the calculation of the treatment plan device in the second and subsequent treatment irradiations. The difference in the amount of line distribution is controlled by the corrected control data of the corrected beam amount. The particle beam therapy device according to claim 1, wherein the linear quantity distribution calculation device includes a database that stores a ratio coefficient, which is a ratio of a particle amount of the beam amount of the particle beam. The z-direction line quantity distribution is a line quantity distribution of the traveling direction of the particle beam; the x-direction line quantity distribution is a line quantity distribution in the x direction perpendicular to the traveling direction of the particle beam; and the y-direction line quantity a distribution is a linear quantity distribution in a y direction perpendicular to a traveling direction of the particle beam and the x direction, and the total line amount calculating unit selects a selected proportional coefficient and the measured beam energy from the measurement coefficient corresponding to the measured energy. The number of the irradiated particles is multiplied, and when the unit particle beam amount is obtained, the unit particle amount is obtained by multiplying the following line amounts: the z-direction line amount distribution is selected in accordance with the measured energy. Selecting a z-direction line quantity; selecting a x-direction line quantity from the x-direction line quantity distribution corresponding to the position of the x-direction of the measurement beam central axis position and the aforementioned measurement energy; and the line quantity distribution from the y-direction corresponding to the aforementioned measurement The y-direction line amount is selected by selecting the position of the beam center axis position in the y direction and the aforementioned measurement energy. The particle beam therapy apparatus according to claim 2, wherein the database stores an x-direction deflection angle of a deflection angle of the x-direction of the particle beam belonging to the scanning device, and belongs to the scanning device a y-direction deflection angle of the deflection angle of the particle beam in the y direction; wherein the total line amount calculation unit selects the selected x-direction line amount, and the deflection angle from the x direction corresponds to the measurement beam central axis position Selecting the position in the x direction and the aforementioned measurement energy Selecting the x-direction deflection angle to calculate the x-coordinate; and selecting the line amount corresponding to the x-coordinate from the x-direction line quantity distribution as the selected x-direction line quantity; the total line quantity calculation unit is based on selecting the selected y-direction line quantity, Determining the y coordinate from the y-direction deflection angle corresponding to the position of the aforementioned y-direction of the measurement beam central axis position and the selected measurement energy, and calculating the y-coordinate; and selecting the y-direction line quantity distribution corresponding to the foregoing The line amount of the y coordinate is used as the aforementioned y direction line amount. A treatment plan correction method is a modified particle beam therapy program that divides a line amount required for particle beam therapy into a plurality of times and provides a treatment plan for an object to be irradiated by a particle beam therapy device. The treatment plan correction method comprises the following steps: a therapeutic data measuring step of measuring particle beam information of the particle beam generated by the particle beam therapy device at a plurality of times, and collecting measurement beam beam information; total line quantity distribution The calculation step is based on the particle beam information in each time interval in which the particle beam information is measured, and calculates an illumination line quantity distribution given by the particle beam to the illumination object; the line quantity distribution difference calculation step is performed by the calculation The difference in the linear quantity distribution between the distribution of the illumination line quantity and the target line quantity distribution; and the treatment plan correction step, which is the calculus of the difference in the aforementioned line quantity distribution Correcting the corrected beam amount; the particle beam information includes a beam amount, an energy, and a beam center axis position of the particle beam; the measuring particle beam information includes measuring a beam amount, measuring energy, and according to the foregoing The measurement beam center axis position is measured by the deflection information of the beam deflected by the scanning device; in the total line quantity distribution calculation step, the number of the irradiation particles is multiplied by the unit particle beam amount in all time intervals The time interval line amount is added to calculate a line amount of the calculation target point of the irradiation target, wherein the number of the irradiation particles is obtained based on the measurement energy and the measurement beam amount in the same section of the time interval, The unit particle beam amount is a line amount given by one of the particle beams obtained based on the measured energy in the same section of the time interval and the position of the measurement beam central axis.