JP5419483B2 - Rotating irradiation type particle beam medical device - Google Patents

Description

  The present invention relates to a particle beam medical device used in cancer treatment or the like, and more particularly to a rotation irradiation type particle beam medical device capable of rotating around a patient in a rotatable manner.

As a radiotherapy device for cancer treatment, particle beam therapy using protons or heavy ions can irradiate the affected area of cancer more intensively than conventional radiation therapy such as X-rays and gamma rays. It is possible to treat without affecting normal cells. In other words, charged particle beams such as protons and carbon ions have a range determined by energy in the medium, giving a dose almost uniformly from the incident, and there is a maximum dose application called the Bragg peak just before the end of the range. Therefore, it is possible to improve the therapeutic effect by matching this with cancer.
The particle beam medical device may be provided with a rotary irradiation device (rotating gantry) for irradiating a patient from an arbitrary direction. The rotating gantry is configured to rotate the particle beam irradiation unit 360 degrees to irradiate the patient with a charged particle beam from an arbitrary rotation angle.

In a rotational irradiation type particle beam medical device for cancer treatment, a bolus for shaping a beam irradiated to an affected area into an energy distribution corresponding to a lower shape of a lesion is usually used.
As such a conventional rotational irradiation type particle beam medical device, for example, in order to irradiate a beam from a plurality of directions, a bolus corresponding to each irradiation direction is prepared according to the lower shape of the affected part obtained in advance by the treatment planning device. In addition, a technique has been proposed in which this is installed on a rotary table provided in the irradiation apparatus and used by switching. The rotation axis of the rotary table and the center of the beam trajectory are eccentric. Therefore, by rotating the rotary table, the boluses are replaced and placed on the beam trajectory, thereby the beam energy corresponding to multiple irradiation directions. A distribution can be formed (see, for example, Patent Document 1).

JP 2002-224230 A (page 4, FIG. 2)

  In the conventional bolus switching mechanism of the particle beam medical device as shown in Patent Document 1, since the rotating table is used, the size of the structure of the patient proximity part becomes large, and the irradiation nozzle cannot be sufficiently brought close to the affected part. There was a problem. In addition, such a method of rotating the rotary table has a problem in that the structure is complicated, so that the maintainability is poor, and since a motor is used for driving, the operation sound is noisy.

  The present invention was made to solve the above-described problems, and improved the bolus switching method and driving method, making the bolus mounting portion compact, and even when the irradiation nozzle is brought closer to the patient. An object of the present invention is to obtain a rotary irradiation type particle beam medical device capable of securing a sufficient work space.

A rotational irradiation type particle beam medical device according to the present invention is equipped with an irradiation device for introducing a particle beam accelerated by an accelerator to irradiate a patient on a treatment table, and the irradiation device, and around the treatment table together with the irradiation device. In a rotary irradiation type particle beam medical device that includes a rotating frame that rotates, and is configured to be able to irradiate from a plurality of irradiation directions by rotating the rotating frame, the irradiation device is configured to adjust the distribution of irradiated particle beams. In addition, a plurality of boluses prepared in accordance with the irradiation direction in accordance with the patient's lesion are provided on the distal end side of the irradiation apparatus, and a plurality of boluses are provided on the distal end side of the irradiation apparatus in the rotation axis direction of the rotating frame. bolus drive mechanism has been arranged, the plurality of bolus, by the drive mechanism slidably mounted in the direction of the rotation axis of the rotating frame, when the irradiation direction was changed, irradiation changed Switched to bolus corresponding to direction, the distal end side of the irradiation device is movable in the axial direction perpendicular to the axis of rotation of the rotary unit, is obtained by the so that can irradiate is brought closer to the patient.

According to the rotary irradiation type particle beam medical device of the present invention, the irradiation device includes a plurality of boluses prepared in accordance with the irradiation direction in accordance with the lesion of the patient in order to adjust the distribution of the particle beam to be irradiated. Is provided on the front end side of the irradiation device, and a plurality of bolus drive mechanisms are arranged on the front end side of the irradiation device in the direction of the rotation axis of the rotary frame. Attached so as to be slidable in the direction of the rotation axis, switch to a bolus corresponding to the irradiation direction depending on the irradiation direction, and allow the distal end side of the irradiation device to move in a direction perpendicular to the axis of the rotation axis of the rotation frame, approaching the patient. since the so that could irradiation Te, can be reduced an area occupied by the switching mechanism of the bolus, also restricted area by the slide mechanism portion compactness becomes only the sliding direction The order, the physician or operator of the access space can be widely secured, the degree of freedom of treatment work increases.

It is a conceptual diagram which shows the rotation gantry part of the rotary irradiation type particle beam medical device by Embodiment 1 of this invention. It is a conceptual diagram which shows the rotation gantry part of the rotary irradiation type particle beam medical device by Embodiment 2 of this invention. It is explanatory drawing explaining the structure of the irradiation system of a particle beam medical device.

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram of a rotating gantry portion of a rotary irradiation type particle beam medical device according to Embodiment 1 of the present invention. FIG. 1 (a) shows a view seen in the axial direction of a rotating shaft, and FIG. ) Is a partial cross-sectional view seen from the direction of arrow b. Moreover, FIG. 3 is explanatory drawing explaining the structure of the irradiation system of a particle beam medical device.

First, the outline of the configuration of the irradiation system of the particle beam medical apparatus will be described with reference to FIG.
A charged particle beam (hereinafter abbreviated as “particle beam”) sent to the irradiation device of the particle beam medical device is first rotated simultaneously in the X direction and the Y direction by the electromagnet 31 to flatten the irradiation field, and then by the scatterer 32. Further, the flatness is increased by scattering, and then, the width (depth direction) of the Bragg peak of the particle beam is changed according to the cancer treatment thickness by the ridge filter 33, and the cancer depth is adjusted by the range shifter 34. The particle beam is absorbed and finely adjusted, and then the block collimator 35 blocks the particle beam outside the necessary range, and the variable collimator 36 moves a plurality of movable leaves to remove the particle beam. In accordance with the shape (planar direction) of the cancer, finally, the bolus 37 adjusts the range of the particle beam according to the shape of the terminal side (bottom) of the cancer.
In FIG. 3, the variable collimator 36 and the bolus 37 are shown in a perspective view so that the shapes can be easily understood.

  Next, the configuration of the rotary irradiation type particle beam medical device according to the first embodiment will be described with reference to FIG. The rotary gantry of the rotary irradiation type particle beam medical device has a cylindrical rotating frame 2 on which the irradiation device 1 is mounted rotatably supported by a roller 3, and the roller 3 is rotated by a driving device (not shown) to 360 degrees. It is configured to be able to rotate. The irradiation apparatus 1 houses components up to the variable collimator 36 of the irradiation system described with reference to FIG. 3, and a bolus described later is provided on the distal end side (exit side). A particle beam accelerated by an accelerator (not shown) is introduced into the irradiation apparatus 1, shaped according to the irradiation affected area, and irradiated to the affected area of the patient 5 on the treatment table 4.

The irradiation apparatus 1 rotates together by rotating the rotary frame 2 and can irradiate the affected area of the patient 5 from a plurality of irradiation directions. In FIG. 1, as shown to (a), two directions, when the irradiation apparatus 1 exists in the perpendicular | vertical upper direction and 90 degrees rotate and are in a horizontal direction, are illustrated.
The irradiation device 1 is also movable in a direction orthogonal to the axis of the rotation axis of the rotary frame 2 so that the irradiation can be performed by approaching the patient 5.

Boluss 6 a and 6 b corresponding to the bolus 37 described with reference to FIG. 3 are provided in the irradiation nozzle portion on the distal end side of the irradiation apparatus 1. For example, a bolus is formed by three-dimensional processing using a polyethylene rectangular parallelepiped having a size of 150 mm × 150 mm and a thickness of about 100 mm according to the depth of the patient's lesion as seen from the irradiation direction, that is, according to the shape of the bottom surface of the lesion. The surface is constricted to form a concave shape. The energy of the particle beam transmitted through the bolus is adjusted in accordance with the shape of the lesion in the depth direction.
Therefore, the bolus is created in advance by the particle beam therapy planning device in correspondence with the lesion of the affected part for each patient.

When treating a single lesion by irradiating it with particle beams from multiple directions, the shape of the lower part of the lesion seen from that direction differs depending on the irradiation direction of the particle beam. The number of boluses is the same as the number of irradiation directions.
In the case of FIG. 1, since the irradiation directions are two directions of the vertical direction and the horizontal direction, two boluses (A) 6a for the vertical direction and two boluses (B) 6b for the horizontal direction are provided. The two boluses 6a and 6b are arranged on the same plane side by side in the axial direction of the rotation axis of the rotating frame 2, as shown in FIG. And it is configured to be slidable in the direction of the rotation axis and to be switched corresponding to the irradiation direction by sliding.

  A generally known linear motion mechanism may be used as the slide mechanism. A holder (not shown) is fixed to the linear motion mechanism, and the bolus is stored in the holder in advance. For example, an air cylinder 7 is used as a sliding drive mechanism. As shown in FIG. 1 (b), the air cylinder 7 is fixed to the housing side of the irradiation apparatus 1 by a support member, and the rod is connected to the holder, whereby the bolus is moved by the operation of one air cylinder 7. (A) 6a and bolus (B) 6b are driven simultaneously.

Next, the switching operation of the boluses 6a and 6b will be described.
As indicated by a broken line in FIG. 1A, when the irradiation apparatus 1 is at a position vertically above the patient 5, the air cylinder 7 is controlled so that the bolus (A) 6a is positioned on the irradiation axis. The bolus (A) 6a is used to irradiate the affected part of the patient 5 with the particle beam, and then the treatment is performed. Then, the rotating frame 2 is rotated by 90 degrees, and the irradiation device 1 is moved horizontally as indicated by the solid line. Turn to. Next, the air cylinder 7 is operated and slid so that the bolus (B) 6b is positioned on the irradiation axis of the particle beam. Then, the bolus (B) 6b is used to irradiate the particle beam and treat from the horizontal direction.
The switching operation of the boluses 6a and 6b is performed by remote operation in conjunction with the rotation of the rotating frame 2 in accordance with a preset program according to a command from a control device (not shown).
At this time, the shape of the beam penetration portion of the variable collimator 36 described above with reference to FIG. 3 is also changed in accordance with the irradiation direction according to the particle beam treatment plan.

Thus, by remotely controlling the switching of the bolus, it is possible to perform irradiation from a plurality of directions without changing the bolus in one irradiation treatment, and more cancer compared to irradiation from only one direction. It is possible to precisely control the irradiation use area according to the shape of the lesion (so-called remote multi-port irradiation). Also, manual bolus switching is not necessary and the air cylinder can be switched in a short time, thus shortening the treatment time.
When switching a plurality of boluses using a rotary table as shown in Patent Document 1 described in the background art section, the area occupied by the disk-shaped rotary table and its operation unit is wide, and the bolus is mounted. When the irradiated nozzle is brought closer to the patient, or when the doctor or worker approaches the patient, the restricted area is large.

On the other hand, in the present embodiment, the switching of the boluses 6a and 6b is a slide (linear motion) system, and the sliding direction is the rotational axis direction of the rotary frame 2, so that the drive mechanism is also arranged in the rotational axis direction. As a result, the restricted area is only in the sliding direction. In particular, when the irradiation nozzle is in the horizontal direction, the drive mechanism portion does not protrude in the vertical direction. As shown by, it becomes possible to bring the irradiation nozzle closer to the patient. As the particle beam spreads less as close to the patient as possible, the irradiation accuracy increases.
In addition, a wide space for doctors and workers to access the patient can be secured, and movement becomes easier.
Furthermore, since the operating mechanism is a direct acting mechanism and the drive mechanism is an air cylinder, the mechanism is simpler than the rotational drive by a motor, so that the control is simple and the failure rate is low. In addition, switching can be performed quickly and the operation sound is low.

In FIG. 1, the irradiation position of the irradiation apparatus 1 is shown in two directions. However, the irradiation position may be further increased and three or more boluses may be arranged side by side. A more precise control effect can be obtained.
Moreover, although the attachment direction of the air cylinder 7 was made into the right side (patient side of the patient 5) of the housing | casing of the irradiation apparatus 1 in FIG.1 (b), it is good also on the left side.

As described above, according to the first embodiment, the irradiation apparatus is provided with a plurality of boluses for adjusting the distribution of the particle beam to be irradiated corresponding to the irradiation direction, and the plurality of boluses are rotated. It is slidably mounted in the direction of the axis of rotation of the frame, and when the irradiation direction is changed, the bolus corresponding to the changed irradiation direction can be switched so that the operator replaces the bolus in one irradiation treatment. Therefore, switching can be performed in a short time, and the treatment time can be shortened.
In addition, since the bolus is switched by sliding it in the direction of the rotation axis, the area occupied by the bolus switching mechanism can be reduced, and the limited area due to movement is limited to the sliding direction, and the mechanism is made compact. Therefore, a wide access space for the doctor or worker can be secured, and the degree of freedom of treatment work is increased.

  In addition, since the plurality of boluses are arranged on the same plane in the direction of the rotation axis of the rotating frame and are driven and switched at the same time, the protrusion of the driving mechanism is reduced and the irradiation nozzle is made closer to the patient. This makes it possible to increase the irradiation accuracy.

Embodiment 2. FIG.
2A and 2B are conceptual diagrams of a rotating gantry portion of a rotary irradiation type particle beam medical device according to Embodiment 2 of the present invention, in which FIG. 2A is a view seen in the axial direction of the rotating shaft, and FIG. It is the fragmentary sectional view seen from the arrow b direction. Parts equivalent to those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The difference is the arrangement of a plurality of boluses and the structure of the drive mechanism. In this embodiment, a plurality of boluses (two cases are shown in FIG. 2) are stacked. Hereinafter, a description will be given based on the drawings.

  As shown in the drawing, the bolus (A) 6 a and the bolus (B) 6 b are stacked in the irradiation nozzle portion of the irradiation apparatus 1 in a direction orthogonal to the rotation axis direction of the rotating frame 2. The boluses 6a and 6b are manufactured in advance corresponding to the lesion and irradiation position of the patient according to the treatment plan. The bolus (A) 6a corresponds to the particle beam from the vertical direction, the bolus (B) 6b corresponds to the particle beam from the horizontal direction, and each bolus 6a, 6b is housed in a holder (not shown), and slide mechanism Is configured to be slidable in the axial direction of the rotary shaft. As shown in FIG. 2B, the driving is performed individually for each of the boluses 6a and 6b by the air cylinder 7 fixed to the housing side of the irradiation apparatus 1.

Next, the bolus switching operation will be described.
In a state where the irradiation apparatus 1 is vertically above the patient, as shown in FIG. 2B, the air cylinder 7 is driven so that the bolus (A) 6a is positioned on the irradiation axis, and the bolus (B) 6b It is retracted to a position deviating from the irradiation axis. Next, when the rotating frame 2 is rotated 90 degrees so that the irradiation device 1 is directed in the horizontal direction as indicated by the solid line (a) and is irradiated from the horizontal direction, the bolus (A) 6a is retracted and the bolus ( B) Operate each air cylinder 7 so that 6b is positioned on the irradiation axis.
In FIG. 2, although the irradiation position is two directions, the irradiation direction may be further increased and the number of boluses may be correspondingly increased.

As described above, according to the second embodiment, the plurality of boluses are stacked and arranged in a direction orthogonal to the rotation axis of the rotating frame, and are individually driven and switched. The protrusion of the direction mechanism portion is smaller than in the case of the first embodiment, the access space for the doctor or the operator is widened, and the degree of freedom of the treatment work is increased.
In addition, since the same shape can be stacked, the manufacturing becomes easy. When the irradiation direction is increased, the number of boluses can be easily added by changing the number of steps.
Furthermore, since the air cylinder is provided individually for the bolus, it may be of a smaller capacity than in the case of the first embodiment, and the control becomes simple.

DESCRIPTION OF SYMBOLS 1 Irradiation device 2 Rotating frame 3 Roller 4 Treatment table 5 Patient 6a Bolus (A)
6b bolus (B) 7 air cylinder 31 electromagnet 32 scatterer 33 ridge filter 34 range shifter 35 block collimator 36 variable collimator 37 bolus.

Claims (3)

An irradiation device that introduces a particle beam accelerated by an accelerator to irradiate a patient on a treatment table, and a rotation frame that is mounted with the irradiation device and rotates around the treatment table together with the irradiation device. In the rotary irradiation type particle beam medical device configured to be able to irradiate from a plurality of irradiation directions by rotating the frame,
In the irradiation apparatus, a plurality of boluses prepared according to the irradiation direction in accordance with the lesion of the patient are provided on the distal end side of the irradiation apparatus in order to adjust the distribution of the particle beam to be irradiated. And a drive mechanism of the plurality of boluses is arranged in the direction of the rotation axis of the rotating frame on the tip side of the irradiation device ,
The plurality of boluses are slidably attached to the rotation axis direction of the rotating frame by the drive mechanism , and when the irradiation direction is changed, the bolus corresponding to the changed irradiation direction is switched to ,
The free end portion of the irradiation device is movable in a direction perpendicular to the axis of the rotating shaft of the rotating frame, rotating irradiation type particle beam medical device being characterized in that the so that can irradiate is brought closer to the patient . In the rotary irradiation type particle beam medical device according to claim 1,
A plurality of the boluses are arranged on the same plane side by side in the direction of the rotation axis, and are simultaneously driven to be switched. In the rotary irradiation type particle beam medical device according to claim 1,
A plurality of the boluses are stacked in a direction perpendicular to the rotation axis direction and are individually driven to be switched.

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