JPH11313900A - Radiation therapy bed system - Google Patents

Abstract

(57) [Problem] To irradiate a patient fixed on the upper surface of a treatment bed from any direction and distance. SOLUTION: A rotary drive mechanism (relative isocentric rotary drive mechanism 60, rolling rotation) for independently rotating the treatment bed 20 about three axes (i, r, p) perpendicular to each other with respect to the patient. And a translation mechanism (X-axis direction) for independently translating the bed 20 in three axes (X, Z, Y) directions perpendicular to each other with respect to the floor. Moving mechanism 30,
A Z-axis direction moving mechanism 40 and a Y-axis direction moving mechanism 50).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation treatment bed system including a bed for fixing a patient when applying radiation irradiated from an irradiation unit to an affected part, and more particularly to a rotary irradiation room. Irradiation from a desired direction and distance to a patient fixed on the bed upper surface, which is suitable for use in a proton therapy apparatus having a gantry (in particular, the irradiation direction is perpendicular to the patient axis) The present invention relates to a radiation treatment bed system capable of realizing non-planar irradiation.

[0002]

2. Description of the Related Art Conventional cancer treatment by radiation includes X-ray,
Gamma rays, electron beams, fast neutrons and the like have been used.
As shown in FIG. 14, since these radiations are the strongest near the body surface, when treating deep cancer,
There is a high possibility that the tissue near the normal body surface will be damaged. On the other hand, the proton beam, which is obtained by stripping electrons from hydrogen atoms, has a positive charge, and has a mass 1836 times that of electrons, is accelerated to a high energy using an accelerator, and the proton beam obtained at a certain depth from the body surface , A Bragg peak P at which the dose is maximized is formed, and then rapidly becomes zero.

[0003] This is because the electric force exerted on electrons by protons is large at a short distance, and when the protons have high kinetic energy and run at high speed, the time to interact with surrounding electrons is short and the ionization amount is small. Just before losing energy and stopping
This is because the action time becomes longer and the ionization amount increases rapidly.

[0004] Therefore, even cancer located deep in the body can be treated without relatively damaging normal cells other than cancer. In addition, since the effect of proton beams on living organisms (RBE) is almost the same as that of X-rays, proton beam therapy can make full use of the accumulated knowledge and experience in conventional X-ray therapy. It also has the advantage. A proton beam therapy device is being introduced as a therapy device that utilizes these characteristics and improves the quality of life by treating without removing functional organs.

[0005] As shown in Fig. 15, such a proton beam therapy system generally comprises a therapy system A, an auxiliary device B, and an auxiliary facility device C.

[0006] The treatment apparatus A, for example, accelerates protons, changes the energy of the extracted proton beam, and limits the spread of energy, and secures a stable orbit of the proton beam. , A beam transport device (BTS) 2 for transporting the beam to the irradiation chamber without loss, a rotating radiation device (gantry) 3 for shaping the proton beam, and accurately irradiating the lesion position on the body with a fixed radiation device 4 inclusive.

[0007] The proton beam accelerator 1 is, for example, a cyclotron, which is an accelerator main body for accelerating protons to an energy of 235 (MeV), and disperses the energy of the proton beam irradiated from the cyclotron as needed. And an energy analyzer (ESS) for changing while limiting.

The rotary irradiation apparatus 3 includes an irradiation section (nozzle) for realizing irradiation requirements such as an irradiation field and an irradiation depth, and a beam transport apparatus (BTS) 2 for conveying a beam to an entrance thereof.
And a structure for performing irradiation at an arbitrary angle equipped with a nozzle attached to the tip of the nozzle and the beam transport device 2, and a device for positioning a diseased part of a patient adjacent thereto. A therapeutic bed system is provided.

The fixed irradiation device 4 is substantially the same as the rotary irradiation device 3, but differs from the rotary irradiation device 3 in that the proton beam emitted from the nozzle is fixed only in the horizontal direction, for example. .

The accessory device B includes a diagnostic device for planning irradiation treatment, a treatment planning system, and a treatment tool machine tool. The diagnostic apparatus includes an MRI, a CT scanner, and an X-ray simulator for confirming the location of an affected part of a patient. The treatment planning system includes hardware, software, and the like for executing an irradiation treatment plan based on the in-vivo affected part information obtained by the diagnostic device. The treatment tool machine includes an NC electric discharge machine, an NC machining center, and an NC for online processing of a patient collimator and a bolus based on an output from a treatment plan.
It is composed of a three-dimensional measuring device. Since the attached device B departs from the gist of the present invention, further description is omitted.

The ancillary equipment C comprises various power supplies mainly composed of a direct current power supply for supplying power to an accelerator and a beam transport equipment, pure water cooling supply equipment for direct cooling of a current conductor (coil), and the like. . In addition, this auxiliary equipment C
Are also out of the gist of the present invention, and further description will be omitted.

[0012] The proton therapy apparatus gives top priority to safety for patients and medical staff from the viewpoint of being a medical apparatus. In terms of driving, its safety,
Operability and ease of maintenance are being pursued. This system adopts a cyclotron as an accelerator, and compared to other accelerator systems, the characteristics of the beam generated from the cyclotron are that the maximum current value can be increased (up to 300 nA), the current value and the beam shape Is extremely small, the time variation of the beam irradiation position is very small, and it can take various structures from a continuous beam to a pulse beam in terms of time structure.

Another major feature of the cyclotron other than the beam characteristics is that the equipment to be adjusted during steady-state operation of the accelerator is 3
Unlike other accelerators that add magnetic field fluctuations and high-frequency fluctuations positively, the cyclotron has a constant magnetic field, so MRI and CT are susceptible to fast magnetic field fluctuations. It is possible to cite characteristics such as hardly affecting the performance of a simulator or the like. These features of the cyclotron bring the following features to the proton beam therapy system.

(1) Since the therapeutic irradiation can be performed stably in time and space by the accelerator itself, the system after the accelerator is simplified and reliable (for example, the irradiation field is φ20c).
If it is less than m, a structurally simple and stable scattering method can be adopted.

(2) Appropriate irradiation can be performed without restraining the patient for a long period of time in correspondence with the affected part position that varies regularly and irregularly with the patient's breathing.

(3) As therapeutic irradiation, it has the ability to cope with various three-dimensional irradiation which is an ideal irradiation form in the near future.

(4) The rise and fall time of irradiation is short, the time for treatment is long, the operation is simple, and there is no need for an operator who has knowledge and experience of the accelerator.

(5) It is easy to take measures against magnetic field fluctuation and high frequency fluctuation noise for medical electronic equipment.

From the point of view of the whole proton beam therapy system, patients,
Devices around the radiation treatment unit, which medical staff must access on a daily basis, are more important than accelerators in terms of ensuring safety and exhibiting irradiation and driving performance. As described above, the configuration around the irradiation treatment unit includes the irradiation device and the patient positioning device, and it is necessary to give the highest priority to ensuring the safety of these components.

With regard to safety measures, basically, the concept of fail-safe shall be thoroughly implemented, and the implementation of safety measures for the equipment itself, such as the basic safety design of electric machines and the selection of materials to prevent radiation deterioration, etc. Of course,
It is necessary to incorporate measures for patients and measures for medical staff assuming various cases. For example, just to ensure patient safety, prevent excessive dose irradiation exceeding the set dose, prevent gantry structure drive, picture tube drive, bed drive, etc. Ensure patient safety emergency evacuation, prevent accidental fall of equipment when replacing patient collimator and bolus,
It is necessary to consider various accidents, such as detecting abnormalities during irradiation of the patient himself and responding to safety emergency, and incorporate safety measures.

The function required around the irradiation treatment part is to irradiate the affected part according to the irradiation conditions created by using the treatment planning system, that is, to achieve the planned dose distribution and dose value for the affected part to be irradiated. And irradiating the proton beam within an allowable error. To achieve these,
It is required that the irradiation position of the affected part of the patient with respect to the beam be determined with high accuracy, and that the planned dose distribution be accurately realized by various beam shaping devices arranged in the nozzle.

In order to satisfy the former requirement, the position of the affected part of the patient is determined by first setting the beam axis and the irradiation center of the affected part to the reference marking on the surface of the affected part using a cross laser pointer installed in the nozzle and in the irradiation space. The horizontal and vertical rough decisions were made by matching, and then the
DRR (DigitalRad) that performs image reconstruction using electronic signals
The procedure is performed in such a manner that the bed is moved so that the horizontal and vertical X-ray image information of the affected part of the patient obtained from the iography reconstruction apparatus is matched with the irradiation position set in the treatment plan, thereby performing precise positioning. As a prerequisite for precise positioning, it is required that sufficient positional accuracy including reproducibility of the beam axis (nozzle) and the irradiation center position be ensured.

The latter dose distribution requirement is basically solved if the beam characteristics are sufficiently stable in time and space, including reproducibility, within the representative time related to the treatment. Half of the measurement of the dose distribution before irradiation treatment using a phantom made of water that mimics the absorption of the human body,
It depends on how accurate it can be and can be implemented in a short time.

In the treatment of cancer by irradiation, it is ideal to concentrate a lethal dose only on the cancer tissue so that the surrounding normal tissue is not irreparably affected. As shown in FIG. 14, by taking advantage of the property that the proton beam incident on the substance gives the maximum dose at the Bragg peak P immediately before stopping, only the cancer tissue is covered with the Bragg peak P, It is to realize the ideal.

Incidentally, the proton beam obtained from the accelerator is in the form of a narrow beam, and its energy (the depth of the Bragg peak) is constant. On the other hand, cancer tissues have various sizes and complicated shapes, the depth in the body is not constant, and the density of the tissue through which proton beams have to pass is not uniform. Therefore, in order to perform proton therapy, the proton beam is expanded to a beam wide enough to irradiate the entire cancer at one time, and the energy is adjusted according to the depth of the cancer. In order to be able to irradiate uniformly, give an energy distribution according to the thickness of the cancer.
It is necessary to make corrections according to the contours of the cancer and the unevenness of the tissue through which the proton beam passes.

Further, the proton beam adjusted in accordance with the shape and depth of the cancer in this way is accurately irradiated on the cancer tissue in the patient's body according to the irradiation conditions, so that the dose distribution and the dose value are as planned. Therefore, it is necessary to irradiate within an allowable error.

In order to realize this, it is necessary not only to accurately realize the planned dose distribution with an irradiation field forming device such as a bolus or a collimator, but also to accurately determine the irradiation position of the patient with respect to the beam.

In the proton beam therapy apparatus as described above, a very high quality proton beam is generated from the cyclotron as an accelerator, and the proton beam irradiated from the nozzle toward the affected part is irradiated with the beam axis (nozzle) and the irradiation center. The positioning accuracy, including the reproducibility of the position, is sufficiently ensured.Accordingly, the bed serving as a treatment table for moving and positioning the affected part of the patient also has a corresponding weight of several tens of kg. A position where the human body such as a water sac that is soft and soft compared to a solid such as stone is moved quickly and accurately with minimal delay due to inertial force, and the proton beam emitted from the nozzle exerts its maximum efficiency Until then, a positioning drive means must be provided so that the affected part can be positioned. In the event of a disaster such as an earthquake, the radiation of the proton beam must be stopped immediately, and the bed on which the patient is placed must be fixed at a certain position.

[0029]

However, the bed used in the conventional radiotherapy or the like is inserted uniaxially into the irradiation room with the patient fixed, and the irradiation part is placed around the axis of the patient. However, it was not possible to realize irradiation from arbitrary directions and distances required for proton beam therapy, in particular, non-planar irradiation in which the irradiation direction was not perpendicular to the patient axis.

The present invention has been made in order to solve the above-mentioned problems, and realizes irradiation of a patient fixed on the upper surface of a treatment bed from an arbitrary direction and a distance, particularly non-planar irradiation. Is the first task.

According to the present invention, a bed for fixedly holding a human body can be transported to any position in a certain space, and the direction of the bed can be freely set, and the bed can be set at a long position. A second object is to be able to adjust the time, and to apply a brake to a portion supporting the bed against unexpected vibration such as an earthquake.

[0032]

SUMMARY OF THE INVENTION The present invention provides a radiation treatment bed system including a bed for fixing a patient when radiation irradiated from an irradiation unit is applied to an affected part for treatment. Pivoting means for independently pivoting about three axes perpendicular to each other with respect to the patient; and translation means for independently translating the bed in directions of three axes perpendicular to each other with respect to the floor. Is provided to solve the first problem. Further, when the bed is inserted into the irradiation room from outside the irradiation room, the center of the rotation is located in the irradiation room.

[0033] Further, a hinge base provided with a rolling rotation drive means for rotating the bed about the longitudinal direction thereof as a center axis, and a longitudinal end of the bed supported by the hinge base. A bed base provided with a pitching rotation driving means for rotating and tilting a bed surface, and a bed support having a relative isocentric rotation driving means for supporting the bed base and rotating the bed base in X and Y plane directions. It is configured using a table.

The rolling rotation drive means may be provided with a handle mechanism for manually rotating the bed about its longitudinal direction as a center axis.

A Y-axis slide plate provided with Y-axis driving means for driving the parallel moving means in the Y-axis direction before and after moving the bed or the bed mounting table from the outside of the irradiation chamber to the irradiation chamber; Z that drives the slide plate in the vertical Z-axis direction
It comprises an upper and lower table provided with shaft driving means and a pedestal provided with X-axis driving means for driving the upper and lower tables in the left and right X-axis directions.

A brake mechanism can be provided between the hinge base, the bed base, the bed mounting base, the Y-axis slide plate, the upper and lower bases, and the base for supporting desired ones.

Further, the bed is provided with an acceleration sensor for detecting acceleration generated in each of the three-dimensional directions.
An acceleration sensor for the rotation means (rolling rotation driving means, pitching rotation driving means, relative isocentric rotation driving means) and the parallel moving means (Y axis driving means, Z axis driving means, X axis driving means); Control means for issuing a drive command in the direction in which the output of the motor decreases.

A brake mechanism by friction and a brake mechanism by fitting can be provided between the upper and lower bases and the pedestal.

The rotating means (rolling rotation driving means, pitching rotation driving means, relative isocentric rotation driving means) and the parallel moving means (Y axis driving means,
Desired driving means of the Z-axis driving means and the X-axis driving means) can be driven by negative feedback control for controlling the command position and the current position to always keep the same position.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, as shown in FIG. 1, an irradiation unit 12 of a proton beam 14 is rotatable around a treatment bed 20 for fixing a patient.
An embodiment of the present invention applied to a proton therapy device having a 00 is described in detail.

According to the first embodiment of the present invention, as shown in FIG. 2, a bed 20 for fixing a patient 10 when a proton beam 14 irradiated from an irradiation unit 12 is applied to an affected area for treatment.
In a therapeutic bed system comprising:
In the horizontal (horizontal) direction (X-axis direction) parallel to the plane including the rotation direction of the irradiation unit 12 as shown by the arrow A in FIG.
An X-axis direction moving mechanism 30 including a slide base 34 that can move in parallel on a slide rail 32 fixed to a preparation room 110 (see FIG. 1) in front of the rotating gantry 100 so as to be movable to Sx; The Z-axis direction including the upper and lower bases 42 fixed on the slide base 34 for allowing the bed 20 to move in the vertical (height) direction (Z-axis direction) Sz perpendicular to the X-axis direction. The moving mechanism 40 is fixed to the upper part of the upper and lower bases 42 so as to be movable in the front-rear (longitudinal) direction (referred to as the Y-axis direction) Sy which enters the rotating gantry 100 from the preparation chamber 110 shown in FIG. A Y-axis direction moving mechanism 50 including a bed mounting table 54 slidable on the base plate 52 in the Sy direction;
With the isocentric axis (i
The bed mounting table 54 for allowing θi rotation (referred to as relative isocentric rotation) around an axis 62.
A relative isocentric rotation drive mechanism 60 attached near the tip of the gantry side, and a bed base 64 fixed to the upper end of the i-axis 62 of the relative isocentric rotation drive mechanism 60. And a rolling rotation driving mechanism 70 for making the rotation freely (referred to as rolling rotation) around a rolling axis (r-axis) 72 which is the axial direction of the patient 10.
The bed 20 is arranged on a turntable 74 rotated by 0. A pitching axis (p-axis) perpendicular to the axis of the patient 10.
A pitching rotation drive mechanism 80 is provided to allow θp rotation (referred to as pitching rotation) freely around 82.

In FIG. 2, B is an irradiation center (referred to as an isocenter).

As shown in FIG. 1, the irradiating section 12 is configured to be rotatable around the bed 20 along the inner peripheral surface of the rotating gantry 100. As shown in FIG. 15, the irradiation unit 12 includes a cyclotron and an energy analyzer (ESS) for accelerating the proton, changing the energy of the extracted proton beam, and restricting the spread of the energy. An accelerator 1 and a beam transport device 2 for securing a stable orbit of the proton beam generated by the proton accelerator 1 and transporting the proton beam to the rotating gantry 100 with a small loss are connected.

The i-axis 62 of the relative isocentric rotary drive mechanism 60 is offset with respect to the movement center line of the Z-axis direction movement mechanism 40 (the center line 42C of the upper and lower bases 42) so as to be offset. It can be adjusted to an arbitrary position by the axial moving mechanism 50 and can be located in the rotating gantry 100.

Next, the operation of this embodiment will be described.

In the treatment of a patient, the body position at the time of treatment in consideration of the shape, depth and direction of the organ to be treated, the direction of the nozzle emitting the proton beam and its position are calculated during the treatment simulation, and their position data are calculated. Is input to the control system of the diseased part positioning apparatus in a coordinate system (for example, X, Y, Z coordinate system) convenient for the operator using the proton beam therapy system. The input data (position and angle) is the position of the bed 20 in the X-axis, Y-axis, and Z-axis directions, i-axis (relative isocentric rotation), p-axis (pitching rotation), and r-axis (rolling rotation). The coordinates are converted as the rotation angle and the position of the affected part of the patient, and each axis of the bed captures the converted data as input position data, and drives each axis to move the affected part of the patient to a desired position. At this time, when the position of the patient obtained by the simulation is not good, the position of the patient is finely adjusted.

The bed 20 is centered on the isocenter B.
FIG. 3 shows a state in which is rotated, and FIG. 4 shows a state in which non-planar irradiation in which the irradiation direction of the proton beam 14 is not perpendicular to the axis of the patient 10 is performed.

In the present embodiment, the i-axis 62 of the relative isocentric rotation is offset with respect to the center line 42 c of the upper and lower bases 42 of the Z-axis direction moving mechanism 40 so that the i-axis 62 can be disposed in the rotating gantry 100. Therefore, alignment with the irradiation unit 12 is easy. Note that the i-axis 62 can be located outside the rotating gantry.

Next, a second embodiment of the present invention, which embodies the first embodiment, will be described in detail.

This embodiment is similar to the first embodiment in the X-axis direction moving mechanism 30, the Z-axis direction moving mechanism 40, the Y-axis direction moving mechanism 50, the relative isocentric rotation driving mechanism 6
0, a rolling rotation drive mechanism 70, and a pitching rotation drive mechanism 80. Corresponding portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

X-axis direction moving mechanism 30 in this embodiment
As shown in detail in FIG. 5, the slide rail 32 of FIG.
Is fixed to the bottom surface 114 of the pit 112 dug on the floor of the preparation room 110 shown in FIG.
(In this embodiment, L = 2200 mm). On the upper surface of the pit 112, an endless belt-like access floor 116 connected to an endless belt and moving with the movement of the slide base 34 in the Sx direction.
(See FIG. 1) to facilitate access of the patient and the operator to the rotating gantry 100.

In FIG. 5, reference numeral 118 denotes a semi-moon-shaped guide plate for turning the access floor 116 while holding the access floor 116 at both ends in the moving direction. This is an axial guide rail (see FIG. 5).

The Z-axis direction moving mechanism 40 in the present embodiment
As shown in detail in FIG. 5, the telescopic cylinder 43 for driving the upper and lower bases 42 in the vertical Z-axis direction Sz is, for example, 3
Even if the depth D of the pit 112 is not large, it is sufficient to move a sufficient distance in the Z-axis direction (H in this embodiment).
= 700 mm).

The Y-axis direction moving mechanism 50 in the present embodiment
As shown in detail in FIG. 6 and FIG.
An electric motor 56 and a torque limiter 57 disposed near the inner rear end, a feed screw 58 rotated by the motor 56, and fixed inside the bed mounting table 54 screwed with the feed screw 58. And a sufficient moving distance E in the Y-axis direction (E in the embodiment).
= 1600 mm) (see FIG. 10).

As shown in detail in FIG. 7, the relative isocentric rotary drive mechanism 60 in the present embodiment has an i-axis 6
2, an electric motor 66 for rotating and driving the bed base 64 is included, and rotates relative isocentricly by a sufficient relative isocentric rotation angle (± 90 ° in the embodiment). It has been like that.

As shown in detail in FIGS. 7 and 8, the rolling rotation drive mechanism 70 in this embodiment includes a gear mechanism 76 for rotating the bed 20 around the r-axis 72 and a manual handle 78. Is composed of
As shown in FIG. 9, the bed 20 on which the patient 10 is placed is
The rolling rotation is performed around the r-axis 72 by a sufficient rolling rotation angle (± 5 ° in the embodiment).

As shown in detail in FIGS. 7, 8, and 10, the pitching rotary drive mechanism 80 in the present embodiment is configured to rotate the bed 20 around a p-axis 82 supported by a bearing 84.
With a sufficient pitching rotation angle θp (± 3 in the embodiment).
°), an electric motor 86 for rotating by pitching, a gear mechanism 87, and a torque limiter 88.

FIG. 11 shows a planar movement state of the bed 20 in the second embodiment.

Next, a third embodiment of the present invention will be described in detail.

In this embodiment, an X-axis direction moving mechanism 30, a Z-axis direction moving mechanism 40, and a Y
An axial movement mechanism 50, a relative isocentric rotation drive mechanism 60, a rolling rotation drive mechanism 70, and a pitching rotation drive mechanism 80 are provided. Corresponding portions are denoted by the same reference numerals, and detailed description is omitted. .

FIG. 12 is a perspective view for explaining the degree of freedom of the bed 20 of the present embodiment. This bed system has a pedestal 115 fixed to a floor surface 114.
The pedestal 115 is formed in an elongated shape and is fixed to the floor surface in the X-axis direction. The pedestal 115 is provided with a slide base 34 slidably in the X-axis direction. To describe the actual structure of the slide base 34,
The slide rails 32 are laid, and the rails are provided with a plurality of holes 33 every several centimeters. The slide base 34 is provided with wheels that roll on the rail 32, and the slide base 34 is mounted on the rail 32
Move on. A brake shoe is provided on the slide base 34, and the brake shoe narrows the rail 32 instead of narrowing the wheel, thereby fixing the slide base 34 to the pedestal 115. The brake mechanism may have a structure in which the brake shoe clamps the periphery of the wheel to stop the slide base 34 on the rail, as is conventionally known.
The slide base 34 is provided with a brake rod for an emergency stop, so that the slide base 34 moves on the rails in an abnormal state due to vibration such as an accident or an earthquake even though the brake is operating. In this case, the emergency brake is actuated, the brake rod protrudes on the rail 32, fits into the hole 33 on the rail 32, and
4 is fixed on the rail 32.

The pulse motor 12 fixed to the base 115
2, a screw rod 124 is rotatably provided on the pedestal 115, while the slide base 34 has
Ball screw 1 screwed with this screw rod 124
26 are attached. Therefore, when the pulse motor 122 is rotated by the position command signal sent from the affected part positioning system of the patient, the slide base 34 can be accurately moved in the X-axis direction in proportion to the rotation angle. The pulse motor 122 is provided with a pulse coder 123 for detecting an amount of relative movement with respect to the pedestal 115, and the amount of relative movement of the slide base 34 with respect to the pedestal 115 is determined using the amount of detection of the pulse coder 123 as a feedback amount. With the negative feedback control, the position of the slide base 34 can be controlled more accurately.

An upper and lower table 42 is fixed on the slide base 34 so as to be vertically expandable and contractible. A vertical position command signal sent from a control system of the patient's affected part positioning apparatus allows a Y-axis attached to the tip of the table. The shaft slide plate 52 is moved in the vertical direction (Z-axis direction). The upper and lower bases 42 are theoretically a rigid structure, and are structures that expand and contract only in the vertical direction. Therefore, in actuality, it is a combination of a tower structure made of sturdy steel frames so that the amount of distortion due to vibration and impact falls within a negligible range for the entire drive system. These towers slide by the telescopic cylinder 43 driven by driving, and the height of the upper and lower bases 42 is substantially adjusted. The upper and lower tables 4
2 also has a position detector such as an inductosin, for example, and can perform height control by feedback similar to that of the slide base 34 based on the vertical position signal obtained from the position detector. Although not shown in detail in the drawing, a brake structure is provided on a slide portion of each of the upper and lower bases 42 formed by splicing of the seals, and the operation of the upper and lower bases 42 can be fixed in an emergency.

The Y-axis slide plate 52 fixed to the distal ends of the upper and lower bases 42 is formed to be elongated in the Y-axis direction. The Y-axis slide plate 52 is accurately oriented in the Y-axis direction, and is connected to the distal ends of the upper and lower bases 42 at the center thereof. Y
The shaft slide plate 52 has a substantially rigid structure. Although not shown, a pedestal 115 is provided on the Y-axis slide plate 52.
A rail similar to that described above is provided.
Are mounted so as to be movable in the Y-axis direction. Although not shown in detail in the drawing, a brake mechanism is provided on the bed mounting table 54, and the operation thereof can be fixed to the Y-axis slide plate 52 in an emergency. The bed mounting table 54 is moved in the Y-axis direction by the Y-axis position command signal sent from the control system of the affected part positioning system of the patient. The Y-axis slide plate 52 is also provided with a position detector such as an inductosin, for example, to detect the relative position of the bed mounting table 54 with respect to the Y-axis slide plate 52 and to obtain the vertical position obtained therefrom. Based on the signal, the Y-axis control can be performed by the same feedback as the slide base 34.

As shown in FIGS. 12 and 13, the bed mounting table 54 is provided with a short isocentric shaft (i-axis) 62 which rotates about the Z-axis. A relative isocentric rotation drive mechanism 60 for rotating 62 is provided. The amount of rotation is determined by a rotation position command signal sent from the control system of the patient's affected part positioning device, and rotates the bed base 64 attached to the tip thereof around the i axis 62 parallel to the Z axis by θi degrees. The relative isocentric rotation drive mechanism 60 is provided with a rotation detector, such as a rotation encoder, for detecting the rotation angle of the i-axis 62 relative to the bed table 54, and detects the rotation angle of the rotation shaft. In addition, it is possible to perform relative isocentric angle rotation feedback control using the rotation position signal obtained therefrom as a feedback signal.

As shown in detail in FIG. 12, and in particular in FIG.
The bed base 64 is provided with a hinge mechanism 130, and rotates a hinge base 132 that supports the bed 20 on which the patient is placed, about a pitching axis (p-axis) on the bed base 64. This amount of rotation is performed by a rotation position command signal sent from a control system of the patient's affected part positioning device. 134
Is a p-axis motor for rotating the p-axis, which is constituted by a pulse motor, and provided with a rotary encoder 136 for detecting the rotation angle of the rotary shaft. In addition,
Also in the p-axis control, the rotation angle of the rotation shaft is detected by the rotation encoder, and the pitching angle rotation negative feedback control using the rotation position command signal obtained therefrom as a feedback signal can be performed. Of course, a brake mechanism is also provided on the p-axis.

The hinge stand 132 has an r-axis motor 14 for swingingly rotating the bed 20 with respect to a rolling axis (r-axis).
0 is provided. The r-axis motor 140 is provided with a rotation encoder 142 for detecting a rotation angle of the r-axis. The bed base 64 is provided with a brake mechanism so that the operation of the bed 20 can be fixed to the bed base 64 in an emergency. The bed 20 is moved by the position command signal sent from the control system of the patient's affected part positioning device.
Rotate along an axis. The relative position of the bed 20 with respect to the hinge table 132 is detected by a signal from the rotary encoder 142, and based on the position signal obtained from this, the same roll angle control as that of the slide base 34 can be performed based on feedback.

Basically, the bed 20 is rotated and oscillated with respect to the r-axis. However, actually, the bed 20 can be manually operated by a handle 78 provided at the tip of the bed 20.
It can be rotated about an axis. This rotation amount is incremental with respect to the rotation position amount obtained from the rotation encoder 142. In order to obtain the incremental amount, the rotation encoder 79 is attached to the shaft of the handle 78.
Is provided. The bed 20 is actually held rotatably by a bearing 22 with respect to the r-axis. On the other hand, the rotating shaft of the handle 78 and the r-axis supporting the bed 20 are connected by a gear mechanism 76, and the housing of the gear mechanism 76 is fixed to the bed 20. This gear mechanism 76
Can rotate the bed 20 freely with respect to the r-axis by rotating the handle 78. However, the handle 76 does not rotate even when the r-axis rotates, for example, by using a worm gear mechanism. Therefore, when the r-axis is rotated by the r-axis motor 140, the handle 76 does not rotate, and the bed 20 is swung. At the tip of the bed 20, there are provided acceleration sensors 26 for detecting accelerations in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively.

The treatment table is constructed so as to be robust as a whole, and can be regarded as almost all rigid. However, a bed 20 at the end where each axis is connected in series, and a human body of several tens of kg is placed at the end. In this case, the position of the bed 20, that is, the affected part position is lower than the position of the bed 20 in the unloaded state, but the distortion amount is simulated and corrected when the patient is actually moved to a predetermined position. Also, during treatment, due to displacement of the human body due to respiration, fine vibrations may occur in the entire system of the treatment table, which may cause displacement of the affected part. In the treatment table according to the present embodiment, the time constant of each axis at the time of no load is measured in advance and set as a known value. Therefore, the overall frequency of the bed 20 when the weight of the human body is mounted on the bed 20 can be calculated by simulation. When the acceleration sensor 26 detects accelerations in the x-axis direction, the y-axis direction, and the z-axis direction during the treatment, a vibration signal having the same magnitude as the direction of the detected acceleration is added to each axis. Thus, control is performed to stop the position of the affected part of the patient.

In this embodiment, all the mechanisms can be driven by electric power. However, any mechanism can be operated only manually.

In the above embodiment, the present invention is used for a proton beam therapy system, but the present invention is not limited to this. The same applies to other radiotherapy systems such as X-rays and electron beams. Obviously, it can be applied to

[0072]

According to the present invention, it is possible to irradiate a patient fixed on the upper surface of a treatment bed from an arbitrary direction and a distance, and to perform irradiation with high accuracy to enhance the treatment effect. .

In particular, in the case where a handle mechanism for manually rolling the bed around the longitudinal direction as the center axis is provided, the bed can be finely moved manually.
The affected part can be finely adjusted to an optimal position for irradiation.

In the case where a brake mechanism is provided between a desired one of the hinge table, the bed base, the bed mounting table, the Y-axis slide plate, the upper and lower tables, and the pedestal, and a portion supporting these. Can be braked on each of the rotating and moving parts,
Even if a person or the like enters the gantry during the adjustment time and unexpectedly collides with any part of the treatment table, it is possible to resume safe and accurate radiation therapy without causing a positional shift in the bed.

An acceleration sensor for detecting accelerations generated in three-dimensional directions is provided on the bed, and a driving command is issued to the translation means and the rotation means in a direction in which the output of the acceleration sensor decreases. In the case where the means is provided, even if the bed tries to vibrate somewhat, the acceleration sensor catches the vibration and drives the bed in the direction opposite to the vibration direction, so that the bed can maintain the home position.

When a brake mechanism by friction and a brake mechanism by fitting are arranged side by side between the upper and lower bases and the pedestal, the brake by friction is used in normal operation, but it is used in an accident or earthquake. If the upper and lower bases suddenly start to move with respect to the base during a disaster, the brake by fitting will operate and the entire treatment base will be fixed to the base, so the treatment base will slide on the base and destroy the drive mechanism etc. There is no such thing.

Further, the rotational moving means (rolling rotational driving means, pitching rotational driving means, relative isocentric rotational driving means), parallel moving means (Z axis driving means, Y
Desired driving means among the axis driving means and the X-axis driving means)
In the case of driving by negative feedback control that always keeps the command position and the current position at the same position, the affected part can be introduced to an accurate position, and the accurate position can be accurately maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of an arrangement relationship between the first embodiment of the present invention and a rotating gantry and a preparation room.

FIG. 3 is a plan view showing an irradiation state on a patient in the first embodiment.

FIG. 4 is a perspective view showing a state in which non-planar irradiation is performed on the patient.

FIG. 5 is an X-axis direction moving mechanism and Z according to a second embodiment of the present invention.
Cross-sectional view showing the axial movement mechanism

FIG. 6 is a plan view showing a Y-axis direction moving mechanism.

FIG. 7 is a longitudinal sectional view showing a rolling rotation driving mechanism and a relative isocentric rotation driving mechanism.

FIG. 8 is a plan view showing a rolling rotation driving mechanism and a pitching rotation driving mechanism.

FIG. 9 is a transverse cross-sectional view showing a rolling rotation state.

FIG. 10 is a longitudinal sectional view of the same.

FIG. 11 is a plan view showing the state of irradiation on the patient.

FIG. 12 is a perspective view showing a degree of freedom of a treatment table according to a third embodiment of the present invention.

FIG. 13 is an enlarged perspective view showing the degree of freedom of the rotary drive mechanism.

FIG. 14 is a diagram showing a comparison of deep dose distributions in various radiations including proton beams.

FIG. 15 is an overall configuration diagram of a proton therapy system.

[Explanation of symbols]

 A: Treatment device B: Auxiliary device C: Auxiliary equipment device 1: Proton beam accelerator device 2: Beam transport device 3, 100: Rotating irradiation device (gantry) 4: Fixed irradiation device 10: Patient 12: Irradiation unit 14: Proton beam DESCRIPTION OF SYMBOLS 20 ... Treatment bed 26 ... Acceleration sensor 30 ... X-axis direction moving mechanism 32 ... Slide rail 34 ... Slide base 40 ... Z-axis direction moving mechanism 42 ... Vertical table 43 ... Telescopic piston 50 ... Y-axis direction moving mechanism 52 ... Y-axis Slide plate 54 ... Bed mounting table 60 ... Relative isocentric rotation drive mechanism 62 ... Isocentric shaft (i-axis) 64 ... Bed base 70 ... Rolling rotation drive mechanism 72 ... Rolling shaft (r-axis) 76 ... Gear mechanism 78 ... Handle 80 ... Pitching rotation drive mechanism 82 ... Pitching axis (p-axis) 110 ... Preparation room 130 ... Hinge mechanism 132 ... Hinge

Claims (9)

[Claims] 1. A radiation treatment bed system including a bed for fixing a patient when treating radiation irradiated from an irradiation unit on an affected part, wherein the bed is formed of three axes perpendicular to each other with respect to the patient. A rotating means for independently rotating around the bed; and a parallel moving means for independently and translationally moving the bed in directions of three axes perpendicular to each other with respect to the floor surface. Radiation therapy bed system. 2. The radiation treatment apparatus according to claim 1, wherein when the bed is inserted into the irradiation chamber from outside the irradiation chamber, the center of the rotation is located in the irradiation chamber. Bed system. 3. A hinge table according to claim 1, wherein said rotating means includes rolling rotation driving means for rotating said bed about its longitudinal direction as a center axis, and said bed supported by said hinge table. A bed base provided with pitching rotation drive means for rotating a longitudinal end portion to tilt the bed surface; and a relative isocentric rotation drive means for supporting the bed base and rotating the bed base in the X and Y plane directions And a bed mounting table provided with the radiation treatment bed. 4. The radiation treatment bed system according to claim 3, wherein said rolling rotation drive means includes a handle mechanism for manually rotating the bed about its longitudinal direction as a center axis. 5. The Y-axis according to claim 1, wherein said parallel moving means comprises: Y-axis driving means for driving said bed or bed mounting table in a Y-axis direction before and after going from outside the irradiation chamber to the irradiation chamber. A slide plate; an upper and lower table provided with a Z-axis drive unit for driving the Y-axis slide plate in the vertical Z-axis direction; and a pedestal provided with an X-axis drive unit for driving the upper and lower table in the left and right X-axis direction. A bed system for radiation therapy, comprising: 6. The method according to claim 3, wherein
Radiation characterized in that a brake mechanism is provided between a part supporting the desired one of the hinge table, the bed base, the bed mounting table, the Y-axis slide plate, the upper and lower tables, and the pedestal. Treatment bed system. 7. The method according to claim 1, wherein
An acceleration sensor for detecting acceleration generated in each of the three-dimensional directions is provided on the bed, and a control means for generating a drive command in a direction in which the output of the acceleration sensor decreases with respect to the rotation means and the translation means is provided. A bed system for radiation therapy characterized by the above. 8. The radiation treatment bed system according to claim 5, wherein a brake mechanism by friction and a brake mechanism by fitting are both provided between the upper and lower bases and the pedestal. 9. A driving means according to claim 3, wherein a desired driving means of said rotating means and parallel moving means is driven by negative feedback control for controlling the command position and the current position to always keep the same position. A bed system for radiation therapy characterized by being performed.