JP7479797B2 - Treatment planning device and radiation therapy system - Google Patents

Description

Embodiments of the present invention relate to a treatment planning device and a radiation therapy system.

In radiation therapy planning, the treatment site, such as the tumor location, is determined based on X-ray CT images, i.e., images showing radiation attenuation (CT value) as light and dark, or ultrasound B-mode images, i.e., images showing the position and intensity of echoes as light and dark. However, it is difficult to accurately capture the composition of tissues using only radiation attenuation information, and the tumor recognition rate is lower using only ultrasound B-mode images compared to CT.

JP 2006-18099 A JP 2011-167330 A JP 2016-112285 A JP 2018-121841 A

The problem that this invention aims to solve is to accurately determine the location of a tumor in radiation therapy planning.

The treatment planning device according to the embodiment includes an acquisition unit that acquires elasticity information from ultrasound elastography and blood flow information from ultrasound Doppler analysis for a target patient, a property evaluation unit that determines the properties of a tumor contained in the target patient based on the elasticity information and the blood flow information, and a display unit that displays the properties.

FIG. 1 is a diagram showing the configuration of a radiation therapy system according to this embodiment. FIG. 2 is a diagram showing the configuration of the treatment planning system of FIG. FIG. 3 is a diagram showing a typical flow of a treatment plan implemented by execution of a treatment plan program by the processing circuitry. FIG. 4 is a diagram showing an example of an elasticity image. FIG. 5 is a diagram showing an example of a blood flow image. FIG. 6 is a diagram showing an example of a composite image of an X-ray CT image and a tumor region of a blood flow image.

The treatment planning device and radiation therapy system according to this embodiment will be described below with reference to the drawings.

Figure 1 is a diagram showing the configuration of a radiation therapy system 1 according to this embodiment. As shown in Figure 1, the radiation therapy system 1 has a treatment planning CT device 2, an ultrasound diagnostic device 3, a treatment planning device 4, and a radiation therapy device 5, which are connected to each other via a network.

The treatment planning CT device 2 is an X-ray computed tomography device for generating CT images used in treatment planning. For example, the treatment planning CT device 2 irradiates a patient with X-rays from the X-ray tube while rotating a rotating frame holding an X-ray tube and an X-ray detector at high speed, and detects the X-rays that pass through the patient with the X-ray detector. Based on the raw data from the X-ray detector, the treatment planning CT device 2 then generates an X-ray CT image that represents the spatial distribution of the X-ray attenuation coefficients of materials on the path of transmission of the X-rays. The X-ray CT images generated by the treatment planning CT device 2 are also called treatment planning CT images.

The ultrasound diagnostic device 3 transmits ultrasound into the patient via an ultrasound probe, receives ultrasound reflected from within the patient via the ultrasound probe, and performs signal processing on the echo signal corresponding to the received ultrasound to generate an ultrasound image. For example, B-mode processing or Doppler processing is used as the signal processing. The ultrasound diagnostic device 3 performs B-mode processing on the echo signal to generate a B-mode image that represents the spatial distribution of the acoustic impedance difference within the patient, and performs Doppler processing on the echo signal to collect blood flow motion information (hereinafter, blood flow information). The ultrasound diagnostic device 3 can also collect elasticity information within the patient's body using ultrasound elastography technology. Examples of ultrasound elastography that can be used include train elastography, which measures tissue distortion while applying pressure to the patient manually via an ultrasound probe, and shear wave elastography, which measures the propagation speed of shear waves generated within the patient's body by applying high-intensity ultrasound pulses (push pulses).

The treatment planning device 4 is a computer that creates a treatment plan based on the CT images from the treatment planning CT device 2 and the blood flow information and/or elasticity information from the ultrasound diagnostic device 3. Details of the treatment planning device 4 will be described later.

The radiation therapy device 5 is a device that treats a patient by irradiating a target tumor or the like in the patient with radiation according to a treatment plan. Specifically, the radiation therapy device 5 has a treatment gantry, a treatment bed, and a console. The treatment gantry supports the irradiation head so that it can rotate around a rotation axis. The irradiation head is equipped with an acceleration tube that accelerates electrons generated by an electron gun or the like, and a metal target against which the electrons accelerated by the acceleration tube collide. X-rays, a type of radiation, are generated when the electrons collide with the metal target. The irradiation head irradiates radiation according to a treatment plan planned by the treatment planning device 4. The treatment bed has a treatment tabletop on which the patient sits, and a base that supports the treatment tabletop so that it can be moved freely. The treatment tabletop has a planar shape similar to the imaging tabletop. The treatment gantry, treatment bed, and patient are aligned so that the patient's treatment area coincides with the isocenter.

In the radiation therapy system 1, a magnetic resonance imaging device (MRI device) may be used instead of the treatment planning CT device 2. The MRI device 2, for example, irradiates RF pulses from an RF coil to excite target nuclei present in a patient placed in a static magnetic field, and collects MR signals generated from the target nuclei using the RF coil. The MRI device 3 then generates MR images that represent the spatial distribution of the target nuclei based on the MR signals from the RF coil. The MR images are used for treatment planning instead of X-ray CT images. In the following explanation, it is assumed that the radiation therapy system 1 includes the treatment planning CT device 2.

Figure 2 is a diagram showing the configuration of the treatment planning device 4 in Figure 1. As shown in Figure 2, the treatment planning device 4 has a processing circuit 41, a communication interface 42, a display device 43, an input interface 44, and a memory circuit 45.

The processing circuitry 41 has, as hardware resources, processors such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit), and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The processing circuitry 41 executes a program related to a treatment plan (hereinafter referred to as a treatment plan program) to execute an information acquisition function 411, a property evaluation function 412, an OAR setting function 413, an image generation function 414, a treatment plan function 415, and a display control function 416.

In the information acquisition function 411, the processing circuitry 41 acquires information necessary for the treatment plan regarding the patient for whom the treatment plan is to be created. For example, the processing circuitry 41 acquires an X-ray CT image from the treatment planning CT device 2, and acquires blood flow information and elasticity information from the ultrasound diagnostic device 3. If the X-ray CT image, blood flow information, and elasticity information are stored in advance in the memory circuitry 45, the processing circuitry 41 acquires the X-ray CT image, blood flow information, and elasticity information from the memory circuitry 45.

In the characteristic evaluation function 412, the processing circuitry 41 determines the characteristics of the tumor contained in the target patient based on the elasticity information and the blood flow information. For example, the processing circuitry 41 sets an image region in which the hardness value is higher than a threshold value based on the elasticity information as the tumor region, and determines the characteristics for each small region of the tumor region based on the blood flow information. A small region may be a single pixel or a collection of multiple pixels.

In the OAR setting function 413, the processing circuitry 41 sets an image region (hereinafter, OAR region) corresponding to the organ at risk (OAR) in the X-ray CT image based on the blood flow rate in the blood flow information.

In the image generation function 414, the processing circuit 41 generates various images. For example, the processing circuit 41 generates an elasticity image showing the spatial distribution of elasticity information and a blood flow image showing the spatial distribution of blood flow information. The processing circuit 41 also generates an image for observing the characteristics of a tumor (hereinafter referred to as an observation image). For example, the processing circuit 41 generates a characteristic image showing the spatial distribution of the tumor characteristics. The processing circuit 41 also generates a composite image of a characteristic image and an elasticity image, a composite image of a characteristic image and blood flow information, and a composite image of a characteristic image and an X-ray CT image. The processing circuit 41 can also generate a two-dimensional image by performing three-dimensional image processing on a three-dimensional image. As the three-dimensional image processing, rendering such as volume rendering, surface rendering, pixel value projection processing, MPR (Multi-Planer Reconstruction) processing, and CPR (Curved MPR) processing may be used.

In the treatment planning function 415, the processing circuitry 41 creates a treatment plan based on the X-ray CT images. At this time, the processing circuitry 41 creates a treatment plan according to the characteristics of the tumor.

In the display control function 416, the processing circuitry 41 displays various information via the display device 43. Specifically, the processing circuitry 41 displays two-dimensional characteristic images and composite images generated by the image generation function 414 via the display device 43. The processing circuitry 41 also displays the treatment plan created by the treatment planning function 415 via the display device 43.

The communication interface 42 communicates data between the treatment planning CT device 2, the ultrasound diagnostic device 3, and the radiation therapy device 5 that constitute the radiation therapy system 1, via wired or wireless connections (not shown).

The display device 43 displays various information using the display control function 416. The display device 43 may be, for example, a CRT display, a liquid crystal display, an organic EL display, an LED display, a plasma display, or any other display known in the art. The display device 43 may be a projector.

The input interface 44 specifically includes an input device and an input interface circuit. The input device accepts various commands from the user. Examples of input devices that can be used include a keyboard, a mouse, and various switches. The input interface circuit supplies output signals from the input device to the processing circuit 41.

The memory circuitry 45 is a memory device such as an HDD (hard disk drive), SSD (solid state drive), or integrated circuit memory device that stores various information. The memory circuitry 45 may also be a drive device that reads and writes various information to and from portable storage media such as a CD-ROM drive, DVD drive, or flash memory. For example, the memory circuitry 45 stores a treatment plan program, X-ray CT images, blood flow information, elasticity information, treatment plans, etc.

Below, an example of the operation of the treatment planning device 4 according to this embodiment will be described. Figure 3 is a diagram showing a typical flow of a treatment plan realized by the execution of a treatment planning program by the processing circuitry 41. Note that the following example of operation is a clinical example of the bladder area.

First, the processing circuitry 41 acquires elasticity information and blood flow information from the ultrasound diagnostic device 3 by implementing the information acquisition function 411 (step S1). In addition, in step S1, the processing circuitry 41 acquires a CT image from the treatment planning CT device 1. The elasticity information may be acquired as an elasticity image, or may be acquired as elasticity information as raw data of the elasticity image. Similarly, the blood flow information may be acquired as a blood flow image, or may be acquired as blood flow information as raw data of the blood flow image. Note that in step S1, ultrasonic elastography and ultrasonic Doppler analysis are performed by the ultrasound diagnostic device 3, and the elasticity information and blood flow information are transmitted to the treatment planning device 4 in real time.

When step S1 is performed, the processing circuitry 41 identifies the tumor area based on the elasticity information by implementing the property evaluation function 412 (step S2). In step S2, the processing circuitry 41 identifies the tumor area, for example, from an elasticity image. The elasticity image is generated by the processing circuitry 41 based on the elasticity information by implementing the image generation function 414.

Figure 4 is a diagram showing an example of elasticity image I1. As shown in Figure 4, elasticity image I1 shows the spatial distribution of elasticity information. Elasticity information is, for example, hardness values such as displacement and elastic modulus. Each pixel value in the elasticity image is assigned a color value according to the hardness value. Cancer cells have the property of becoming hard, and areas with high hardness are more likely to be cancerous cells. Therefore, the processing circuit 41 performs threshold processing on elasticity image I1 and extracts image areas with values higher than the threshold as tumor areas.

When step S2 is performed, the processing circuitry 41 classifies the tumor region into high activity regions and low activity regions based on the blood flow information by implementing the property evaluation function 412 (step S3). In step S3, the processing circuitry 41 classifies the tumor region into high activity regions and low activity regions using, for example, a blood flow image. The blood flow image is generated by the processing circuitry 41 based on the blood flow information by implementing the image generation function 414.

Figure 5 is a diagram showing an example of the blood flow image I2. As shown in Figure 5, the blood flow image I2 shows the spatial distribution of blood flow information. The blood flow information includes blood flow amount and blood flow direction. Each pixel of the blood flow image I2 is assigned a color value according to the blood flow amount and blood flow direction. It is estimated that the part of the tumor with a large blood flow amount is more activated, and the part with a small blood flow amount is inactivated. Therefore, the processing circuit 41 first aligns the elasticity image I1 and the blood flow image I2, and matches the tumor region R2 in the blood flow image I2 with the tumor region R1 in the elasticity image I1. Note that the matrix sizes of the blood flow image I2 and the elasticity image I1 may be the same or different. Next, the processing circuit 41 compares the blood flow amount of each pixel with a threshold value limited to the tumor region R2 of the blood flow image I2, and classifies pixels with a blood flow amount greater than the threshold value into a high activity region R21, and classifies pixels with a blood flow amount less than the threshold value into a low activity region R22. Pixels classified into the high activity region R21 are given a label indicating high activity (hereinafter, a high activity label), and pixels classified into the low activity region R22 are given a label indicating low activity (hereinafter, a low activity label). High activity can also be said to mean high malignancy, and low activity can also be said to mean low malignancy.

In the above process, the tumor area is classified into two types: low activity area and high activity area. However, it may be classified into three types: low activity area, medium activity area, and high activity area, or may be classified into more areas.

In the above process, the regions are classified into two types, low activity regions and high activity regions, based on the blood flow rate, but they may also be classified into low activity regions and high activity regions based on the blood flow rate and blood flow direction. If the blood flow rate flowing into a tumor is greater than the blood flow rate flowing out of the tumor, it is estimated that the tumor is more likely to be activated. Therefore, the processing circuit 41 may assign pixels for which the subtraction value of the blood flow rate flowing out of each pixel from the blood flow rate flowing into that pixel is greater than a threshold value to a high activity region, and assign pixels for which the subtraction value is less than the threshold value to a low activity region.

In the above process, each pixel in the tumor region is classified as a low activity region or a high activity region, but each group of adjacent pixels may also be classified as a low activity region or a high activity region.

After step S3 is performed, the processing circuitry 41 generates a composite image of the X-ray CT image and the elasticity information or blood flow information by implementing the image generation function 414 (step S4). Specifically, the processing circuitry 41 may generate a composite image of the X-ray CT image and the entire elasticity image or blood flow image, or may generate a composite image of the X-ray CT image and the tumor region of the elasticity image or blood flow image. The synthesis process is performed, for example, by alpha blending technology.

In step S4, the processing circuitry 41 generates a two-dimensional image of an MPR section that coincides with the scanning plane of the elasticity image or blood flow image from the three-dimensional X-ray CT image (volume data). Specifically, the processing circuitry 41 acquires position information of the ultrasound probe attached to the ultrasound diagnostic device 3 in real time in parallel with the elasticity information and blood flow information by implementing the information acquisition function 414. The position information of the ultrasound probe may be position information of any sensor, such as a magnetic sensor or a GPS (Global Positioning System) sensor provided on the ultrasound probe. Since the coordinate system of the position information and the coordinate system of the three-dimensional X-ray CT image are associated in advance, the processing circuitry 41 can calculate an MPR section that coincides with the scanning plane of the elasticity image or blood flow image based on the position information of the ultrasound probe.

Once step S4 has been performed, the composite image is displayed with high activity areas and low activity areas differentiated (step S5).

Figure 6 is a diagram showing an example of a composite image I4 of an X-ray CT image I3 and a tumor region R2 of a blood flow image. As shown in Figure 6, the X-ray CT image I3 and the tumor region R2 are aligned and composited by the processing circuit 41. The tumor region R2 is classified into a high activity region R21 and a low activity region R22 in step S3. The processing circuit 41 displays the high activity region R21 labeled with a high activity label and the low activity region R22 labeled with a low activity label with different visual effects. For example, the outline of the high activity region R21 and the outline of the low activity region R22 may be displayed in different colors, or the entire area of the high activity region R21 and the entire area of the low activity region R22 may be displayed in different colors. In addition, different marks or symbols may be attached to the high activity region R21 and the low activity region R22.

By observing the composite image I4, doctors and other medical professionals can easily identify the high and low activity areas classified based on ultrasound elastography and ultrasound Doppler analysis.

After step S5 is performed, the processing circuitry 41 creates a treatment plan by implementing the treatment planning function 415 (step S6). In step S6, the processing circuitry 41 creates a treatment plan based on the X-ray CT image. There are two types of treatment plan creation methods: forward planning and inverse planning. In forward planning, the radiation therapy conditions, such as the number of radiation irradiation directions, each irradiation angle, radiation intensity, collimator opening, and wedge filter, are set in detail, and the radiation distribution finally obtained under those conditions is observed to evaluate the radiation therapy conditions. When changing the radiation distribution, some or all of the radiation therapy conditions are changed and the radiation distribution is obtained again. In this way, in forward planning, the radiation distribution is changed little by little while changing the radiation therapy conditions, and the radiation conditions are changed repeatedly until the desired radiation distribution is achieved. Inverse planning sets the tumor region and an appropriate margin, and sets the radiation dose and tolerance range to be irradiated to that region. Furthermore, the OAR region is extracted from the medical image, and the radiation dose for the OAR region is set to a safety level that does not exceed a predetermined level. Radiation therapy conditions are determined based on the characteristics of the tumor.

In the process of creating a treatment plan, the processing circuitry 41 adjusts, for example, the dose distribution that was initially set according to the properties of the high activity region and the low activity region. For example, the dose distribution of the high activity region may be increased by a predetermined value, and the dose distribution of the low activity region may be decreased by a predetermined value. The predetermined value can be set to any value via the input interface 44, etc. Furthermore, the processing circuitry 41 may increase the dose distribution of the high activity region according to the blood flow rate, and may decrease the dose distribution of the low activity region according to the blood flow rate.

In this way, according to this embodiment, a treatment plan can be created taking into account the characteristics of the tumor. This can improve the accuracy and reliability of the treatment plan. By adjusting the dose distribution according to the characteristics, radiation therapy can be performed more efficiently.

In addition, during the process of creating a treatment plan, the processing circuitry 41 may set an OAR region in the X-ray CT image based on blood flow information by implementing the OAR setting region function 415. Specifically, the processing circuitry 41 aligns the blood flow image and the X-ray CT image, generates a composite image of the aligned blood flow image and the X-ray CT image, and sets the OAR region based on the blood flow information. For example, large blood vessels with a large blood flow, such as coronary arteries, aorta, carotid arteries, and lower limb arteries, are OAR. Therefore, the processing circuitry 41 applies threshold processing to the blood vessel image and sets the image region where the blood flow is higher than the threshold as the OAR region. The threshold may be set to a blood flow rate that can distinguish between the blood flow rate of large blood vessels and the blood flow rate of relatively thin blood vessels. The image region of the X-ray CT image that is at the same coordinate as the OAR region of the blood vessel image is set as the OAR region.

After the OAR region is set, the processing circuitry 41 adjusts the dose distribution so that the OAR region is not given a specified dose. This allows medical personnel to create a treatment plan that takes into account the OAR, which has a high blood flow.

This completes the treatment plan realized by the execution of the treatment plan program by the processing circuit 41.

The operation example shown in FIG. 3 can be modified in various ways. For example, in step S4, the processing circuitry 41 may not generate a composite image of the X-ray CT image and the elasticity image or blood flow image. For example, in step S5, the processing circuitry 41 may display the X-ray CT image and the elasticity image side by side, the X-ray CT image and the blood flow image side by side, or the X-ray CT image, the elasticity image, and the blood flow image side by side. The processing circuitry 41 may also display the X-ray CT image and the composite image of the elasticity image and the blood flow image side by side. The processing circuitry 41 may also display the composite image of the X-ray CT image and the elasticity image and the blood flow image side by side, or the composite image of the X-ray CT image and the blood flow image and the elasticity image side by side.

The tumor region may be identified based on the blood flow information, and the distribution of the properties of the tumor region may be identified based on the elasticity image. For example, it may be considered that the harder the tumor, the more malignant the tumor. In this case, the processing circuitry 41 may set the image region in which the blood flow rate is higher than a threshold value as the tumor region, set the image region in which the stiffness value is higher than the threshold value as a high-grade region, and set the image region in which the stiffness value is lower than the threshold value as a low-grade region.

According to this embodiment, the tumor area can be identified based on elasticity information from ultrasound elastography and blood flow information from ultrasound Doppler analysis. This makes it possible to identify the tumor area taking into account the characteristics of the tumor, compared to identifying the tumor area using X-ray CT images. According to this embodiment, the characteristics of the tumor are displayed, so medical personnel can grasp the tumor position taking into account the characteristics.

According to at least one of the embodiments described above, the tumor position can be accurately captured in radiation therapy planning.

The term "processor" used in the above description means a circuit such as a CPU, a GPU, or an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The processor realizes its function by reading and executing a program stored in a memory circuit. Instead of storing a program in a memory circuit, the processor may be configured to directly incorporate the program into its circuit. In this case, the processor realizes its function by reading and executing a program incorporated in the circuit. Instead of executing a program, a function corresponding to the program may be realized by a combination of logic circuits. Each processor in this embodiment is not limited to being configured as a single circuit for each processor, but may be configured as a single processor by combining multiple independent circuits to realize its function. Furthermore, the multiple components in FIG. 1 and FIG. 2 may be integrated into a single processor to realize its function.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and gist of the invention.

Reference Signs List 1 Radiation therapy system 2 CT image for treatment planning 3 Ultrasound diagnostic device 4 Treatment planning device 5 Radiation therapy device 41 Processing circuit 42 Communication interface 43 Display device 44 Input interface 45 Memory circuit 411 Information acquisition function 412 Property evaluation function 413 OAR setting function 414 Image generation function 415 Treatment planning function 416 Display control function

Claims (11)

an acquisition unit that acquires elasticity information by ultrasonic elastography and blood flow information by ultrasonic Doppler analysis regarding a target patient;
a characteristic evaluation unit that determines a characteristic of a tumor contained in the target patient based on the elasticity information and the blood flow information;
A display unit that displays the property;
A treatment planning apparatus comprising:
The characteristic evaluation unit sets an image region having a stiffness value higher than a first stiffness threshold as a tumor region based on the elasticity information, and determines the characteristics for each small region of the tumor region based on the blood flow information. the blood flow information includes blood flow rate;
the property evaluation unit assigns a small region having a blood flow rate greater than a first blood flow threshold to a high activity, and assigns a small region having a blood flow rate less than a second blood flow threshold to a low activity;
The treatment planning system of claim 1. The blood flow information includes a blood flow amount and a blood flow direction,
the property evaluation unit assigns a small region in which a subtraction value of the blood flow rate flowing out of the small region from the blood flow rate flowing into the small region is greater than a third blood flow threshold to a high activity, and assigns a small region in which the subtraction value is smaller than a fourth blood flow threshold to a low activity.
The treatment planning system of claim 1. The treatment planning device according to claim 2 or 3, wherein the display unit displays the areas assigned to the low activity and the areas assigned to the high activity in a distinguishable manner. an image generating unit that generates a composite image of at least one of an elasticity image showing a spatial distribution of the elasticity information and a blood flow image showing a spatial distribution of the blood flow information, and the spatial distribution of the property;
The display unit displays the composite image.
2. The treatment planning system of claim 1. The apparatus further includes an image generating unit that generates a composite image of a CT image by X-ray computed tomography or an MR image by a magnetic resonance imaging device regarding the target patient and a spatial distribution of the property,
The display unit displays the composite image.
The treatment planning system of claim 1. The treatment planning device of claim 1 further comprises a setting unit that sets an OAR region in a CT image obtained by X-ray computed tomography or an MR image obtained by a magnetic resonance imaging device for the target patient based on the blood flow rate in the blood flow information. The treatment planning device according to claim 1, further comprising a treatment planning unit that creates a treatment plan according to the property. an acquisition unit that acquires elasticity information by ultrasonic elastography and blood flow information by ultrasonic Doppler analysis regarding a target patient;
a determination unit that determines at least one of the activity and malignancy of each small region of the tumor region included in the subject patient based on the elasticity information and the blood flow information;
a display unit that displays the tumor region by distinguishing the characteristics of each of the small regions ;
The determination unit sets an image region having a stiffness value higher than a first stiffness threshold as a tumor region based on the elasticity information, and determines the property for each small region of the tumor region based on the blood flow information, or sets an image region having a blood flow rate higher than a first blood flow threshold as a tumor region based on the blood flow information, and determines the property for each small region of the tumor region based on the elasticity information.
Treatment planning device. an ultrasound diagnostic device for acquiring elasticity information by ultrasound elastography and blood flow information by ultrasound Doppler analysis for a target patient;
An apparatus for determining a characteristic of a tumor contained in a target patient based on the elasticity information and the blood flow information, and creating a treatment plan according to the characteristic,
a treatment planning device that sets an image region having a stiffness value higher than a first stiffness threshold as a tumor region based on the elasticity information, and determines the characteristics of each small region of the tumor region based on the blood flow information;
A radiation therapy system comprising: an ultrasound diagnostic device that acquires elasticity information by ultrasound elastography and blood flow information by ultrasound Doppler analysis for a target patient;
and a treatment planning device that determines at least one of the activity and malignancy characteristics of each small region of the tumor region included in the target patient based on the elasticity information and the blood flow information, and creates a treatment plan according to the characteristics .
The treatment planning device sets an image region having a stiffness value higher than a first stiffness threshold as a tumor region based on the elasticity information, and determines the property for each small region of the tumor region based on the blood flow information, or sets an image region having a blood flow rate higher than a first blood flow threshold as a tumor region based on the blood flow information, and determines the property for each small region of the tumor region based on the elasticity information.
Radiation therapy system.