JPH07275383A - Radiotherapy system for use in body cavity - Google Patents

Abstract

PURPOSE:To determine a storage time for a radiation source by automatically calculating a volume of the affected part of a patient in performing a radiotherapy on the affected part of the patient using the radiation source inserted into a body cavity of the patient. CONSTITUTION:A probe 10 is inserted into a bronchus 100. The probe 10 includes a passage for a coupling liquid, a passage for insertion of a guiding tube and an endoscopic optical fiber. The three-dimensional measurement of an affected part 102 is conducted by an ultrasonic diagnosis in which a volume V of the affected part 102 is calculated. An optimum dosage S is determined, based on the volume V of the affected part 102 and a storage time for a radiation source in a body cavity is calculated. A carrying wire provided with a radiation source 32 at an end thereof is introduced in the guiding tube, such that the radiation source 32 is located in a position near the affected part 102.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art An intracorporeal radiotherapy apparatus for treating a bronchial cancer, an esophageal cancer or the like with a sealed radiation source in close proximity has been put into practical use. Such a device is called, for example, an afterloading device.

When performing radiation treatment of bronchial cancer, for example, using this apparatus, first, a guide tube is inserted from the mouth of the patient to the affected part in the bronchus. After the state is confirmed by, for example, X-ray imaging or the like, 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 area. The time set based on the size of the affected area (for example, 3
The radiation source is placed in the body only for 0 minutes. After the elapse of the set time, the fed radiation source is instantaneously stored again in the radiation source storage container. As a method for feeding the radiation source, there are a fixed wire method using a radiation source transfer wire, an air chute method utilizing air pressure, and the like. Further, when the affected area covers a wide area, a plurality of radiation sources may be used in one treatment.

According to the above-mentioned afterloading treatment method, unlike the irradiation from the outside of the body, the radiation can be concentrated on the cancer tissue to prevent the adverse effect on the normal tissue as much as possible, and the therapeutic effect on the cancer tissue can be enhanced. .

In the past, the radiation source was placed in the affected area X for a long time.
The decision was made on the basis of a radiograph, an X-ray CT diagnosis result, or an optical observation result using an endoscope.

[0006]

However, in an X-ray image, some initial cancers are difficult to distinguish from normal tissue, and an endoscope can observe only the wall surface of the body cavity and not the inside of the tissue. Therefore, in any case, it is difficult to easily and accurately obtain the accurate volume of the affected area. Therefore, it is difficult to accurately specify the irradiation dose, that is, the radiation source detention time.

On the other hand, according to ultrasonic diagnosis, even an early stage cancer can be distinguished on an ultrasonic image, and the affected part existing inside the tissue can be observed as a tomographic image. That is,
If the ultrasonic probe in the body cavity is inserted into the body cavity to perform ultrasonic diagnosis of the affected area, the affected area information necessary for the afterloading treatment can be acquired.

However, it is troublesome to sequentially insert and remove the ultrasonic probe in the body cavity, the endoscope, and the guide tube to perform diagnosis and treatment, and the burden on the patient also increases. Moreover, the positioning accuracy of the guide tube is also reduced. 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 thereof is to provide an intracavitary radiotherapy system capable of automatically setting an appropriate dose (radiation source placement time) according to an affected part volume. To do.

Another object of the present invention is to provide an intracavity radiotherapy system capable of measuring the affected part volume by utilizing intracavity ultrasonic diagnosis.

Further, the present invention provides an ultrasonic diagnostic technique in a body cavity,
An object of the present invention is to provide an intracavity radiotherapy system that combines endoscope technology and afterloading technology.

[0012]

In order to achieve the above object, the present invention is a probe which is inserted into a body cavity and which transmits and receives ultrasonic waves to capture echo data and which is for transferring a radiation source. A body cavity ultrasonic probe in which a tube insertion passage through which a guide tube is inserted is calculated, and a volume of a diseased part is calculated based on the echo data, and a dose calculation device that calculates an optimum dose based on the volume, An apparatus for performing radiation treatment by feeding a radiation source into the guide tube from a radiation source storage container, and a radiation treatment apparatus for indwelling the radiation source in the vicinity of the affected area for a time corresponding to the optimum dose. And

The ultrasonic probe in the body cavity is arranged at the tip of the probe tube having flexibility and is inserted into the body cavity. An ultrasonic transducer forming an ultrasonic beam scanning surface in a direction orthogonal to the axial direction,
It is characterized by including.

The body cavity ultrasonic probe is characterized by including an irradiation means for illuminating the inside of the body cavity, and an endoscopic means for observing the inside of the body cavity.

Further, the dose calculation device calculates a diseased part volume based on a three-dimensional echo data memory for storing the echo data, a diseased part data extraction section for extracting echo data of the affected part, and echo data of the affected part. It is characterized by including an affected part volume calculating part and an optimum dose calculating part which calculates an optimum dose for the affected part based on the affected part volume.

The radiation treatment apparatus further includes a dwell time calculating means for calculating a dwell time from the optimum dose, and a transfer for controlling the sending back of the radiation source so that the radiation source is dwelled in the body cavity for the dwell time. And a control means.

[0017]

According to the present invention, when performing radiotherapy for cancer, for example, the ultrasonic probe in the body cavity is first inserted into the body cavity. In that case, the inside of the body cavity is illuminated by the irradiation means provided in the probe, and the inside of the body cavity is observed by the endoscopic means. In other words, the lesion can be searched for while looking at the optical image inside the body cavity.

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

On the other hand, a tube insertion passage is formed in the probe inserted into the body cavity. For example, while inserting the guide tube into the tube insertion passage and observing with the endoscope, the tip of the guide tube is The guide tube itself and the probe are moved so as to be positioned near the affected area.

After the positioning of the guide tube is completed, the radiation source is sent out from the radiation source storage container by the radiotherapy apparatus and passes through the guide tube to reach the tip of the guide tube, that is, the vicinity of the affected area. The radiation source is left as it is for a time that allows the irradiation of the obtained optimum dose, and after the irradiation is completed, the radiation source is stored again in the radiation source storage container.

Therefore, since the indwelling time is controlled in accordance with the volume of the affected area measured by ultrasonic waves, it is possible to irradiate the affected area with an appropriate dose without excess or deficiency. Further, the observation of the affected area by the endoscopic means and the observation of the affected area by the ultrasonic diagnosis can be performed without inserting or removing the probe.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of an intracavity radiotherapy system according to the present invention. The system of the present embodiment is for treating bronchial cancer.

In FIG. 1, this system is roughly classified into an ultrasonic probe for bronchus (hereinafter referred to as a probe) 10
And an ultrasonic diagnostic device 12 connected to the probe 10.
And 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 includes a flexible probe tube 18 that is inserted into the bronchus 100, a tip portion 20 that is provided at the tip of the probe tube 18 for transmitting and receiving ultrasonic waves 104, and a base of the probe tube 18. And a base end portion 22 provided at the end.

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

FIG. 3 shows the inserted state of the probe 10. The tip portion 20 has a built-in ultrasonic transducer 54 and transmits and receives ultrasonic waves. FIG. 4 shows a cross section orthogonal to the axial direction of the probe tube 18 of the tip portion 20. As shown in the figure, the ultrasonic transducer 54 is configured by arranging a plurality of ultrasonic transducers 54a in an annular shape. Therefore, if the ultrasonic beam is radially scanned, a circular ultrasonic beam scanning surface can be formed. It should be noted that a fan-shaped ultrasonic beam scanning surface can be formed by driving only the ultrasonic vibration elements within a certain range among the plurality of ultrasonic vibration elements 54a.

As shown in FIGS. 3 and 4, the probe tube 18
(And the tip portion 20) has, for example, a diameter of 2.
A tube insertion passage 60 of 0 mm is formed. A guide tube 24 described later is inserted into the tube insertion passage 60. An opening 60A that communicates with the tube insertion passage 60 is formed on the tip surface 20A of the tip portion 20.

Further, 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 is composed of an image guide 61 and a light guide 62, both of which are coaxially formed. The end face of the optical fiber 58 appears on the front end face 20A, so that the light guide 62 causes the bronchus 1
The inside of 00 is illuminated, and its optical image is transmitted by the image guide 61.

By the way, the inside of the bronchus 100 is poor in wettability as compared with, for example, the esophagus, and it is difficult to achieve acoustic matching between the tip portion 20 and the inner surface of the bronchus. That is,
If there is a gap between the tip portion 20 and the inner surface of the bronchus, the propagation characteristics of ultrasonic waves deteriorate. Further, the unevenness on the inner surface of the bronchus reduces the adhesion of the tip portion 20.

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 composed of xylocaine jelly, which is a material that does not affect the living body. A flow path 56 having a diameter of 2.0 mm, for example, is formed in the probe tube 18, and the flow path 56 communicates with the discharge hole 56A.
Then, a predetermined amount of 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 sliding. The discharge amount of the coupling liquid is set to such an extent that it does not affect the living body.

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

Returning to FIG. 2, the proximal end portion 22 is provided with an operating portion 50 for operating the bending of the probe tube 18. Specifically, by rotating the knob 52, the rotation thereof is performed. Is transmitted to the wire to bend the bending 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 so as to face the end of the image guide 61, and converts the optical image in the bronchus into an electric signal. The electrical signal is cable 108
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. Figure 2
106 is a cable for connecting the probe 10 and the ultrasonic diagnostic apparatus.

In FIG. 2, a tube receiving opening 22A communicating with the tube insertion passage 60 is formed in the base end portion 22 and a guide tube 24 is inserted therein. When the tube insertion passage 60 and the flow passage 56 are also used as 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, the ultrasonic diagnostic apparatus 12 is an apparatus that supplies a transmission signal to the probe 10 and processes a reception signal. An ultrasonic tomographic image is displayed on the display device 15 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 calculation device 14 temporarily stores the echo data taken in the three-dimensional region of the living body. As shown in FIG. 3, with the probe tube 18 inserted in the bronchus 100, while transmitting and receiving ultrasonic waves 104, the probe tube 20 is moved stepwise on the affected area 102. 18
By gradually pulling back, the three-dimensional echo data acquisition region including the affected part 102 can be formed, and the echo data in the region is stored in the three-dimensional echo data memory 42. The pullback 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 the ultrasonic diagnostic apparatus is instructed to transmit and receive ultrasonic waves each time. In the three-dimensional echo data memory 42, each echo data is associated with data indicating the address of the ultrasonic beam scanning surface.

In FIG. 1, the affected part extraction section 44 indicates the affected part 10 existing in the above-mentioned three-dimensional echo data acquisition region.
Extract the echo data of 2. That is, for example, the process of distinguishing normal tissue from cancer tissue is executed for each echo data, and the coordinates of the affected part surface are specified. The tissue can be distinguished by using, for example, the intensity of the echo data or the variance value. Then, the volume calculation unit 46 calculates the affected part volume V from the identified coordinates of the affected part surface.

The dose calculator 48 calculates the optimum dose S from the affected part volume V. That is, since it is necessary to determine the irradiation dose according to the size of the cancer tissue in order to reduce the irradiation dose to the normal tissue as much as possible and to enhance the therapeutic effect, the optimum dose S is automatically determined based on the affected part volume V. Is calculated.

The radiation source transfer device 16 for performing radiation treatment of cancer by inserting the small sealed radiation source 32 into the body cavity has an irradiation controller 40.
A shield box 26, a guide tube 24, a transfer wire 30, and a transfer mechanism 28. The flexible guide tube 24 has a diameter of 1.5 mm, for example, and is inserted into the tube insertion passage 60 of the probe 10. Similarly, the radiation source 32 is fixed to the tip of the flexible transfer wire 30, and the radiation source 32 can be inserted into the body by feeding the transfer wire 30 into the guide tube 24. Various radioactive elements can be used as the radiation source, for example, iridium or cobalt can be used.

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

The irradiation control unit 40 calculates the irradiation time, that is, the radiation source detention time based on the optimum dose S, and controls the delivery and rewinding of the transfer wire 30 according to the radiation source detention time.

Next, a method for diagnosing and treating bronchial cancer by the system of this embodiment will be described. First, the probe tube 18 is inserted through the mouth of the patient, and the tip portion 20 is guided to the affected area 102. In that case, the lesion is searched while observing the endoscopic image displayed on the display unit 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 coupling liquid is supplied into the bronchus to function as a lubricant. This allows smooth insertion.

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

Then, the probe tube 18 is artificially pulled back at every predetermined distance ΔL, and the ultrasonic beam 104 is scanned each time, and the echo data is captured. That is, the affected part 1
Cut 02 in multiple positions. It should be noted that the coupling liquid improves the acoustic propagation between the distal end portion 20 and the inner surface of the bronchus, so that the echo data can be accurately captured.

After the acquisition of the echo data is completed, the distal end portion 20 is retracted from the affected area 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 affected part 102 under internal observation.

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

After the above preparations are completed, the transfer mechanism 28 sends the transfer wire 30 having the radiation source 32 mounted on the tip thereof into the guide tube 24, and positions the radiation source 32 at the tip of the guide tube 24. The feeding (and retrieving) of the radiation source 32 is performed, for example, within 1 second in order to avoid unnecessary exposure.

Radiation from the radiation source 32 is applied to the affected area,
For example, treatment of cancerous tissue is performed for 30 minutes. Then, after a predetermined detention time has elapsed, the transfer wire 3 is automatically
0 is rewound, the radiation source 32 is stored in the shielding box 26,
Isolated from the outside. Then, after the guide tube 24 is pulled out, if necessary, optical observation or ultrasonic diagnosis of the affected area 102 is executed, 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 according to the volume of the affected area that is ultrasonically measured, it is possible to irradiate the affected area with an appropriate dose that is sufficient. Further, it is possible to perform the observation of the affected area by the endoscopic means, the observation of the affected area by ultrasonic diagnosis, and the insertion of the guide tube, respectively.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a body 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 tip portion.

[Explanation of symbols]

 10 Ultrasonic probe for bronchus 12 Ultrasonic diagnostic device 14 Dose calculation device 16 Radiation source transfer device

Claims (5)

[Claims] 1. A probe which is inserted into a body cavity and transmits and receives ultrasonic waves to capture echo data, for use in the body cavity having a tube insertion passage through which a guide tube for transferring a radiation source is formed. An ultrasonic probe, a dose calculation device that calculates the volume of the affected area based on the echo data, and calculates the optimal dose based on the volume, and a radiation source that sends the radiation source from the radiation source storage container into the guide tube. An intracorporeal radiotherapy system, comprising: a radiotherapy device that is a device for performing treatment, and a radiotherapy device that places a radiation source in the vicinity of an affected area for a time corresponding to the optimum dose. 2. The system according to claim 1, wherein the ultrasonic probe in the body cavity is disposed on a flexible probe tube to be inserted into the body cavity, and at a tip portion of the probe tube. And an ultrasonic transducer for forming an ultrasonic beam scanning surface in a direction orthogonal to the axial direction of the probe tube, and an intracorporeal radiotherapy system. 3. The system according to claim 1, wherein the ultrasonic probe in the body cavity includes an irradiation unit that illuminates the inside of the body cavity, and an endoscopic unit that observes the inside of the body cavity. Intracavitary radiotherapy system. 4. The system according to claim 1, wherein the dose calculation device is a three-dimensional echo data memory that stores the echo data, a diseased part data extraction unit that extracts echo data of a diseased part, and echo data of the diseased part. A body cavity radiotherapy system, comprising: an affected part volume calculation part for calculating an affected part volume based on the above; and an optimal dose calculation part for calculating an optimal dose for the affected part based on the affected part volume. . 5. The system according to claim 1, wherein the radiation treatment apparatus includes a dwell time calculating unit that calculates a dwell time from the optimum dose, and a radiation source is placed in the body cavity for the dwell time. An intracavitary radiotherapy system, comprising: a transfer control unit that controls the return of the source.