JP2758133B2 - Body cavity radiotherapy system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotherapy system in a body cavity, and more particularly to a system for automatically controlling the indwelling time of a radiation source (ray source) in a body cavity according to the volume of an affected part.

[0002]

2. Description of the Related Art An intra-body cavity radiotherapy apparatus for treating a bronchial cancer, an esophageal cancer or the like by approaching a sealed radiation source has been put to practical use. Such a device is called, for example, an afterloading device.

When radiotherapy for bronchial cancer is performed using this device, for example, a guide tube is first inserted from a patient's mouth to an affected area in the bronchi. After the state is confirmed by, for example, X-ray photography, a small radiation source that generates radiation is instantaneously sent from the radiation source storage container into the guide tube, and the radiation source is positioned near the affected part. Then, a time set based on the size of the affected part (for example, 3
The source is left in the body for only 0 minutes). After the elapse of the set time, the fed source is instantly stored again in the source storage container. The method of feeding the radiation source includes a fixed wire method using a radiation source transfer wire and an air chute method using air pressure. Further, when the affected area is extensive, a plurality of radiation sources may be used in one treatment.

According to the after-loading treatment described above, unlike radiation from outside the body, radiation can be concentrated on cancer tissue to prevent adverse effects on normal tissue as much as possible, and the treatment effect on cancer tissue can be enhanced. .

Conventionally, the indwelling time of the radiation source is
The determination was made based on a radiograph, an X-ray CT diagnosis result, or an optical observation result using an endoscope.

[0006]

However, in the X-ray image, certain types of early cancer are difficult to distinguish from normal tissues, and the endoscope can only observe the wall of the body cavity and cannot observe the inside of the tissue. In any case, it has been difficult to easily and accurately determine the exact volume of the affected part. Therefore, it has been difficult to accurately specify the irradiation dose, that is, the indwelling time of the radiation source.

On the other hand, according to the ultrasonic diagnosis, even an initial cancer can be distinguished on an ultrasonic image, and a diseased part existing inside a tissue can be observed as a tomographic image. That is,
By inserting the ultrasonic probe in the body cavity into the body cavity and performing ultrasonic diagnosis of the diseased part, the diseased part information necessary for the after-loading treatment can be obtained.

[0008] However, it is troublesome to sequentially insert and remove the ultrasonic probe, the endoscope, and the guide tube in the body cavity to perform diagnosis and treatment, and the burden on the patient increases. In addition, the positioning accuracy of the guide tube decreases. In addition, an ultrasonic probe for bronchi has not yet been put to practical use.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an intracorporeal radiation therapy system capable of automatically setting an appropriate dose (source placement time) according to the volume of an affected part. Is to do.

[0010] Another object of the present invention is to provide a radiotherapy system in a body cavity capable of measuring the volume of an affected part using ultrasonic diagnosis in the body cavity.

[0011] The present invention also provides an ultrasonic diagnostic technique in a body cavity,
An object of the present invention is to provide an intrabody cavity radiotherapy system that combines an endoscope technique and an afterloading technique.

[0012]

In order to achieve the above object, the present invention relates to a probe inserted into a body cavity to transmit and receive ultrasonic waves and capture echo data. An ultrasound probe for body cavity in which a tube insertion passage through which a guide tube is inserted is formed, a dose calculation device that calculates a volume of an affected part based on the echo data, and calculates an optimal dose based on the volume, An apparatus for performing radiation therapy by sending a radiation source from the radiation source storage container into the guide tube, and including a radiation treatment apparatus for placing the radiation source near the affected part for a time corresponding to the optimal dose. And

[0013] Further, the intracavity ultrasonic probe is disposed at a distal end of the probe tube and a flexible probe tube inserted into the body cavity. An ultrasonic transducer that forms an ultrasonic beam scanning surface in a direction orthogonal to the axial direction,
It is characterized by including.

[0014] Further, the intracavity ultrasonic probe is characterized in that it includes irradiation means for illuminating the inside of the body cavity, and endoscope means for observing the inside of the body cavity.

[0015] The dose calculating device may further include a three-dimensional echo data memory for storing the echo data, an affected part data extracting unit for extracting echo data of the affected part, and an affected part volume based on the echo data of the affected part. And an optimal dose calculator for calculating an optimal dose for the affected part based on the affected part volume.

[0016] The radiation therapy apparatus may further comprise an indwelling time calculating means for calculating an indwelling time from the optimal dose, and a transfer for controlling the sending back of the source so as to be indwelled in the body cavity for the indwelling time. And control means.

[0017]

According to the present invention, for example, when performing radiotherapy for cancer, an intracavity ultrasonic probe is first inserted into a body cavity. In that case, the inside of the body cavity is illuminated by the irradiating means provided on the probe, and the state inside the body cavity is observed by the endoscope means. That is, a lesion can be searched for while looking at the optical image in the body cavity.

When a lesion is found, an ultrasonic diagnosis is performed. For example, a plurality of ultrasonic beam scanning planes are automatically or manually set for the affected part, and three-dimensional echo data of the affected part is captured. Then, the volume of the affected part is calculated based on the three-dimensional echo data, and the optimum dose is further calculated from the affected part volume.

On the other hand, the probe inserted into the body cavity is formed with a tube insertion passage, and a guide tube is inserted into the tube insertion passage, and the end of the guide tube, for example, is observed while observing by the endoscope. The guide tube itself and the probe are moved so as to be positioned near the affected part.

After the positioning of the guide tube is completed, the radiation treatment apparatus sends out the radiation source from the radiation source storage container, passes through the guide tube, and reaches the distal end of the guide tube, that is, the vicinity of the affected part. The radiation source is left as it is for a time during which the obtained optimal dose can be irradiated, and after the irradiation is completed, the radiation source is stored again in the radiation source storage container.

Therefore, the indwelling time is controlled according to the volume of the affected part measured by the ultrasonic wave, so that it is possible to irradiate the affected part with an appropriate dose with no excess or shortage. Further, the observation of the affected part by the endoscopic means and the observation of the affected part by the ultrasonic diagnosis can be performed without inserting and removing the probe.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a radiotherapy system in a body cavity according to the present invention. The system of this embodiment is for treating bronchial cancer.

In FIG. 1, this system is roughly divided into an ultrasonic probe for bronchi (hereinafter referred to as a probe) 10
And the ultrasonic diagnostic apparatus 12 connected to the probe 10
, A dose calculation device 14, and a radiation source transfer device (afterloading device) 16.

First, the probe 10 will be described in detail. The probe 10 has a flexible probe tube 18 inserted into the bronchus 100, a distal end portion 20 provided at the distal end thereof for transmitting and receiving ultrasonic waves 104, and a base of the probe tube 18. And a base end 22 provided at the end.

FIG. 2 shows such a probe.
The probe tube 18 has a length of, for example, 55 cm and a diameter of, for example, 6 mm. The bending portion 18A is connected to an operation portion 5 described later.
It is bent up and down by the operation of 0. In addition, you may be bent left and right further.

FIG. 3 shows an inserted state of the probe 10. The distal end portion 20 has a built-in ultrasonic vibrator 54 for transmitting and receiving ultrasonic waves. FIG. 4 shows a cross section orthogonal to the axial direction of the probe tube 18 at the distal end portion 20. As illustrated, the ultrasonic transducer 54 is configured by arranging a plurality of ultrasonic vibration elements 54a in a ring shape. Therefore, if the ultrasonic beam is radially scanned, an annular ultrasonic beam scanning surface can be formed. In addition, by driving only a certain range of ultrasonic vibration elements among the plurality of ultrasonic vibration elements 54a, a fan-shaped ultrasonic beam scanning surface can be formed.

As shown in FIGS. 3 and 4, the probe tube 18
(And the distal end portion 20) along the axial direction.
A 0 mm tube insertion passage 60 is formed. A guide tube 24 described later is inserted into the tube insertion passage 60. An opening 60 </ b> A communicating with the tube insertion passage 60 is formed in the distal end surface 20 </ b> A of the distal end portion 20.

As shown in FIGS. 3 and 4, an optical fiber 58 is provided in the probe tube 18 along the axial direction. The optical fiber 58 includes an image guide 61 and a light guide 62, both of which are formed coaxially. The end face of the optical fiber 58 is exposed on the tip face 20A, and thus the bronchus 1
00 is illuminated, and the optical image is transmitted by the image guide 61.

The inside of the bronchus 100 has poor wettability compared to, for example, the esophagus, and it is difficult to achieve acoustic matching between the distal end portion 20 and the inner surface of the bronchi. That is,
If there is a gap between the distal end portion 20 and the inner surface of the bronchus, the propagation characteristics of the ultrasonic wave are reduced. In addition, due to the unevenness on the inner surface of the bronchi, the adhesion of the distal end portion 20 is reduced.

Therefore, in this embodiment, the probe 10 is provided with a coupling liquid supply mechanism. Here, the coupling liquid is an acoustic matching material, and is made of xylocaine jelly, which is a material that does not affect the living body. A flow path 56 having a diameter of, for example, 2.0 mm is formed in the probe tube 18, and the flow path 56 communicates with the discharge hole 56A.
A predetermined amount of the coupling liquid is discharged from the discharge hole 56A, and the discharged coupling liquid is interposed between the distal end portion 20 and the inner surface of the bronchus, whereby acoustic matching is achieved. Further, the coupling liquid can be used as a lubricating liquid, and the coupling liquid can be discharged when the probe tube 18 is inserted to improve the slip. The discharge amount of the coupling liquid is set to such an extent that the living body is not affected.

In this embodiment, the tube insertion passage 60
Although the and the flow path 56 are configured separately, both may be used.

Returning to FIG. 2, an operation portion 50 for operating the bending of the probe tube 18 is provided at the base end portion 22. Specifically, when the knob 52 is rotated, the rotation thereof is performed. Is transmitted to the wire to bend the bent portion 18A.

The electric syringe 19 is a device for supplying a predetermined amount of coupling liquid, and is connected to the flow path 56 via a hose 109. The CCD is provided opposite to the end of the image guide 61, and converts an optical image in the bronchus into an electric signal. The electrical signal is
Is sent to the display 15 shown in FIG. The light source 17 in FIG. 1 is a device for supplying light to the light guide 62 via an optical fiber in the cable 108. FIG.
Reference numeral 106 denotes a cable for connecting the probe 10 and the ultrasonic diagnostic apparatus.

In FIG. 2, a tube receiving port 22A communicating with the tube insertion passage 60 is formed in the base end portion 22, and the guide tube 24 is inserted therein. In the case where the tube insertion passage 60 and the flow passage 56 are shared by one through passage, a switch is provided at the base end portion 22.

Next, another configuration in the system will be described in detail.

In FIG. 1, an ultrasonic diagnostic apparatus 12 supplies a transmission signal to the probe 10 and processes a reception signal. The display 15 displays an ultrasonic tomographic image in real time. The echo data 110 output from the ultrasonic diagnostic device 12 is input to the dose calculation device 14.

The three-dimensional echo data memory 42 of the dose calculator 14 temporarily stores echo data captured in a three-dimensional region of a living body. As shown in FIG. 3, with the probe tube 18 inserted into the bronchus 100, the probe tube is moved so that the distal end 20 moves stepwise on the diseased part 102 while transmitting and receiving the ultrasonic waves 104. 18
Is returned step by step, a three-dimensional echo data capturing area including the affected part 102 can be formed, and the echo data in that area is stored in the three-dimensional echo data memory 42. Pulling back of the probe tube 18 is performed manually or automatically. In the case of manual operation, for example, ΔL = 5 mm
The tip is pulled back each time, and each time, the ultrasonic diagnostic apparatus is instructed to transmit and receive ultrasonic waves. In the three-dimensional echo data memory 42, each piece of echo data is associated with data indicating an address of an ultrasonic beam scanning surface.

In FIG. 1, the affected part extraction unit 44 is provided for the affected part 10 existing in the three-dimensional echo data capturing area.
2 is extracted. That is, for example, a process of distinguishing between a normal tissue and a cancer tissue is performed on each piece of echo data, and the coordinates of the diseased part surface are specified. The tissue can be distinguished by using, for example, the intensity or variance of the echo data. Then, the volume calculation unit 46 calculates the affected part volume V from the coordinates of the specified affected part surface.

The dose calculator 48 calculates the optimum dose S from the affected part volume V. That is, in order to reduce the irradiation dose to normal tissues as much as possible and to increase the therapeutic effect, it is necessary to determine the irradiation dose in accordance with the size of the cancer tissue. Is calculated.

The radiation source transfer device 16 for inserting the small sealed radiation source 32 into a body cavity and performing radiation therapy for cancer includes a radiation control unit 40.
, A shielding box 26, a guide tube 24, a transfer wire 30, and a transfer mechanism 28. The flexible guide tube 24 has a diameter of, for example, 1.5 mm, and is inserted into the tube insertion passage 60 of the probe 10. A source 32 is fixed to the tip of the flexible transfer wire 30, and the source 32 can be inserted into the body by feeding the transfer wire 30 into the guide tube 24. As the radiation source, various radioactive elements can be used, for example, iridium and cobalt can be used.

The shielding box 26 functions as a storage container for the radiation source, in which a drum 34 forming a part of a transfer mechanism for feeding and winding the transfer wire 30 is provided. 36 is a guide roller. Note that FIG. 1 shows only the main configuration of the afterloading treatment apparatus. For example, radiation treatment may be performed using a plurality of radiation sources. Further, in the present embodiment, a wire is used, but an air chute method may be adopted.

The irradiation control section 40 calculates the irradiation time, that is, the radiation source placement time based on the optimum dose S, and performs the feeding control and the rewind control of the transfer wire 30 according to the radiation source placement time.

Next, a method for diagnosing and treating bronchial cancer using the system of this embodiment will be described. First, the probe tube 18 is inserted from the patient's mouth, and the distal end portion 20 is guided to the affected part 102. In this case, a lesion is searched for while observing the endoscopic image displayed on the display 15, and the probe tube 18 is bent along the bronchial shape by operating the operation unit 50 shown in FIG. If necessary, a small amount of the coupling liquid is supplied into the bronchi to function as a lubricant. Thereby, insertion can be performed smoothly.

When the affected part is found, as shown by reference numeral 20 'in FIG. 3, the distal end portion 20 is once protruded to the back side from the affected part 102, and the syringe 19 is operated in this state, so that the inside of the bronchi 100 is discharged from the discharge hole 56A. To discharge a fixed amount of coupling liquid.

Then, the probe tube 18 is artificially pulled back at every predetermined distance ΔL, and each time the ultrasonic beam 104 is scanned, echo data is fetched. That is, the affected part 1
02 is sliced at a plurality of positions. Since the sound propagation between the distal end portion 20 and the inner surface of the bronchus is improved by the coupling liquid, the echo data can be captured with high accuracy.

After the acquisition of the echo data is completed, the distal end portion 20 is retracted from the diseased part 102, and the guide tube 2
4 is fed into the tube insertion passage 60, and the distal end of the guide tube 24 is positioned near the diseased part 102 under endoscopic observation.

In parallel with this, the dose calculating device 14 calculates the affected part volume V based on the acquired echo data, and further calculates the optimum dose S. Further, the irradiation control unit 40 calculates the source placement time corresponding to the optimum dose S.

After the above preparation is completed, the transfer mechanism 28 feeds the transfer wire 30 having the radiation source 32 mounted on the distal end into the guide tube 24, and the radiation source 32 is positioned at the distal end of the guide tube 24. The feed-in (and back-out) of the source 32 is performed, for example, within one second to avoid unnecessary exposure.

The radiation from the radiation source 32 is applied to the affected area,
For example, treatment of cancer tissue is performed for 30 minutes. Then, after a predetermined indwelling time has elapsed, the transfer wire 3
0 is rewound, the source 32 is stored in the shielding box 26,
Be isolated from the outside. Then, after the guide tube 24 is pulled out, if necessary, optical observation or ultrasonic diagnosis of the diseased part 102 is performed, and finally the probe tube 18 is pulled out from the bronchus 100.

[0051]

As described above, according to the present invention,
Since the indwelling time is controlled in accordance with the volume of the affected part measured by the ultrasonic measurement, it is possible to irradiate the affected part with an appropriate dose with no excess or shortage. In addition, the observation of the affected part by the endoscope, the observation of the affected part by the ultrasonic diagnosis, and the insertion of the guide tube can be performed without insertion and removal.

[Brief description of the drawings]

FIG. 1 is a view showing the overall configuration of an intrabody cavity radiotherapy system according to the present invention.

FIG. 2 is an external view of an ultrasonic probe for bronchi.

FIG. 3 is a diagram showing a state at the time of treatment.

FIG. 4 is a sectional view of a distal end portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ultrasound probe for bronchi 12 Ultrasound diagnostic device 14 Dose calculating device 16 Source transfer device

Continuation of the front page (56) References JP-A-59-88160 (JP, A) JP-A-62-284658 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61N 5 / Ten

Claims (5)

(57) [Claims] 1. A probe which is inserted into a body cavity to transmit and receive ultrasonic waves to capture echo data, wherein the probe is for use in a body cavity in which a tube insertion passage through which a guide tube for transferring a radiation source is inserted is formed. An ultrasound probe, a dose calculator that calculates the volume of the affected area based on the echo data, and calculates an optimal dose based on the volume, and a radiation source that sends a radiation source from the radiation source storage container into the guide tube. An intracorporeal radiotherapy system, comprising: a radiotherapy device for performing a treatment, wherein the radiotherapy device places a radiation source near an affected part for a time corresponding to the optimal dose. 2. The system according to claim 1, wherein the intracavity ultrasonic probe is disposed at a distal end of the probe tube and a flexible probe tube inserted into the body cavity. And an ultrasonic transducer that forms an ultrasonic beam scanning surface in a direction orthogonal to the axial direction of the probe tube. 3. The system according to claim 1, wherein the intracavity ultrasound probe includes: an irradiation unit that illuminates the inside of the body cavity; and an endoscope unit that observes the inside of the body cavity. Body cavity radiotherapy system. 4. The system according to claim 1, wherein the dose calculation device includes: a three-dimensional echo data memory that stores the echo data; an affected area data extracting unit that extracts echo data of the affected area; and an echo data of the affected area. An intracorporeal radiation therapy system comprising: an affected volume calculating unit that calculates an affected volume based on a diseased volume; and an optimal dose calculating unit that calculates an optimal dose to the affected portion based on the affected volume. . 5. The system according to claim 1, wherein the radiotherapy apparatus comprises: an indwelling time calculating means for calculating an indwelling time from the optimal dose; and a line so that the source is indwelled in a body cavity for the indwelling time. And a transfer control means for controlling the return of the source.