Radiotherapy positioning method and device

Abstract

The invention discloses a radiotherapy positioning method and device, and belongs to the technical field of radiotherapy. The radiotherapy positioning method comprises the following steps: S1, acquiring three-dimensional coordinate information of a radiotherapy target spot through a treatment planning system; s2, performing scanning and three-dimensional reconstruction on the lesion area through an image system to obtain three-dimensional coordinate information of a lesion point; s3, space coordinate conversion is carried out on the three-dimensional coordinate information of the radiotherapy target spot and / or the three-dimensional coordinate information of the focus point, and the radiotherapy target spot and the focus point are placed in the same space coordinate system; s4, calculating an error distance between the radiotherapy target spot and the focus point in the same space coordinate system; and S5, when the error distance is greater than an error threshold value, adjusting the spatial position of the treatment bed, and repeating the steps S2-S4 until the error distance is smaller than the error threshold value. The position of the treatment bed can be automatically adjusted through the treatment bed driving system, manual connection is not needed, and the adjusting efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of radiotherapy technology, and more specifically, to a radiotherapy positioning method and apparatus. Background Technology

[0002] With the continuous development and advancement of medical imaging technology, imaging has begun to be widely used in the field of radiotherapy. Imaging technology enables target positioning of radiotherapy equipment before treatment and real-time image guidance during treatment. However, hemispherical and C-shaped Gamma Knife devices do not have the capability to install real-time guidance imaging systems. However, thanks to the stereotactic positioning accessories and the excellent hardware precision of the Gamma Knife device, a static image positioning system can be installed. This system consists of two sets of X-ray imaging components, employing kV-level X-ray stereotactic plane imaging technology to obtain X-ray projection images in two directions. After three-dimensional reconstruction of the captured images, data is transmitted to the Gamma Knife device to guide the positioning of the treatment bed for the patient.

[0003] A search revealed that Chinese patent CN114917489A discloses a multifunctional head gamma knife treatment device. The device includes a treatment bed base and a treatment bed body above the base. A lifting mechanism, a lateral movement mechanism, and a longitudinal movement mechanism are provided between the treatment bed base and the bed body. The lifting mechanism, lateral movement mechanism, and longitudinal movement mechanism between the treatment bed base and the bed body can adjust the position of the patient for radiotherapy.

[0004] The aforementioned treatment bed relies on manual adjustment and cannot be automatically adjusted based on information from the imaging system, resulting in low efficiency. Therefore, we propose a radiotherapy positioning method and device. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] The purpose of this invention is to provide a radiotherapy positioning method and apparatus to solve the problems mentioned in the background art.

[0007] 2. Technical Solution

[0008] like Figure 1 As shown, the present invention is achieved through the following technical solution:

[0009] A method for radiotherapy localization includes the following steps:

[0010] S1. Obtain the three-dimensional coordinate information of the radiotherapy target through the treatment planning system;

[0011] S2. Scan and reconstruct the lesion area using an imaging system to obtain the three-dimensional coordinate information of the lesion point;

[0012] S3. Perform spatial coordinate transformation on the three-dimensional coordinates of the radiotherapy target and / or the three-dimensional coordinates of the lesion, and place the radiotherapy target and the lesion in the same spatial coordinate system;

[0013] S4. Calculate the error distance between the radiotherapy target and the lesion within the same spatial coordinate system;

[0014] S5. When the error distance is greater than the error threshold, adjust the spatial position of the treatment bed and repeat steps S2-S4 until the error distance is less than the error threshold.

[0015] As an optional solution to the technical solution of this application, in S5, the method for adjusting the spatial position of the treatment bed includes the following steps:

[0016] S501. Calculate the error vector from the radiotherapy target to the lesion point within the same spatial coordinate system;

[0017] S502. Perform a spatial coordinate transformation on the error vector to make its spatial coordinate system consistent with the spatial coordinate system within the treatment bed drive system.

[0018] S503. Adjust the position of the treatment bed according to the converted error vector.

[0019] As an optional solution to the technical solution of this application, step S2 includes the following steps:

[0020] S1. Simultaneously acquire images of the lesion area using at least two modalities of CBCT, kV-level X-ray, MRI, or ultrasound.

[0021] S2. A cross-modal registration algorithm is used to register images of different modalities to the same coordinate system for three-dimensional reconstruction to obtain the three-dimensional coordinate information of the lesion.

[0022] As an optional solution to the technical solution of this application, S2 specifically includes: acquiring the patient's respiratory waveform and collecting the three-dimensional coordinate information of the lesion point at the end of expiration.

[0023] As an optional solution to the technical solution in this application, the error distance is calculated in step S4 using the following method:

[0024]

[0025] In the formula, x1, y1, and z1 are the spatial coordinates of the radiotherapy target; x2, y2, and z2 are the spatial coordinates of the lesion.

[0026] As an optional solution to the technical solution of this application, in S4, the error threshold is 0.5mm.

[0027] As an optional solution to the technical solution of this application, S1 specifically includes: identifying the encryption algorithm of the treatment planning system for the three-dimensional coordinate information of the radiotherapy target, and using a corresponding decryption algorithm to obtain the three-dimensional coordinate information of the radiotherapy target within the treatment planning system.

[0028] 3. Beneficial effects

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1) This application obtains the three-dimensional coordinate information of the radiotherapy target and the lesion, and calculates the error distance between the radiotherapy target and the lesion. When the error distance is greater than the error threshold, the position of the treatment bed can be automatically adjusted by the treatment bed drive system without manual intervention, thus increasing the adjustment efficiency.

[0031] 2) This application realizes the functions of acquiring three-dimensional coordinate information of radiotherapy target and lesion and calculating the error distance between radiotherapy target and lesion through hardware board, which can be applied to different models of Gamma Knife equipment and guide the adjustment of the treatment bed position in Gamma Knife equipment. Attached Figure Description

[0032] Figure 1 This is a logic block diagram of a radiotherapy localization method. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0034] Example 1:

[0035] This invention provides a method for radiotherapy positioning, comprising the following steps:

[0036] S1. Obtain the three-dimensional coordinate information of the radiotherapy target through the treatment planning system;

[0037] S2. Scan and reconstruct the lesion area using an imaging system to obtain the three-dimensional coordinate information of the lesion point;

[0038] S3. Perform spatial coordinate transformation on the three-dimensional coordinates of the radiotherapy target and / or the three-dimensional coordinates of the lesion, and place the radiotherapy target and the lesion in the same spatial coordinate system;

[0039] S4. Calculate the error distance between the radiotherapy target and the lesion within the same spatial coordinate system;

[0040] S5. When the error distance is greater than the error threshold, adjust the spatial position of the treatment bed and repeat steps S2-S4 until the error distance is less than the error threshold.

[0041] By adopting the above method, the spatial coordinates of the lesion and the radiotherapy target can be obtained with the help of the imaging system and the treatment planning system. It can be determined whether the error between the radiotherapy target and the lesion meets the standard. If it does not meet the standard, the spatial position of the treatment bed can be automatically adjusted without manual intervention, thus increasing the adjustment efficiency.

[0042] S1 specifically includes: identifying the encryption algorithm for the three-dimensional coordinate information of the radiotherapy target in the treatment planning system, and using a corresponding decryption algorithm to obtain the three-dimensional coordinate information of the radiotherapy target within the treatment planning system. This enables the method to be applied to treatment planning systems with encryption capabilities.

[0043] S2 specifically includes: acquiring the patient's respiratory waveform, collecting the three-dimensional coordinate information of the lesion point at the end of expiration, ensuring the consistency of the lesion point position during multiple adjustments, and increasing the accuracy and efficiency of adjustment.

[0044] S2 includes the following steps:

[0045] S1. Simultaneously acquire images of the lesion area using at least two modalities of CBCT, kV-level X-ray, MRI, or ultrasound.

[0046] S2. A cross-modal registration algorithm is used to register images of different modalities to the same coordinate system for three-dimensional reconstruction to obtain the three-dimensional coordinate information of the lesion.

[0047] By fusing multimodal data, it is possible to compensate for artifacts or insufficient soft tissue resolution in a single modality.

[0048] In S4, the error threshold is 0.5 mm, and the error distance is calculated using the following method:

[0049]

[0050] In the formula, x1, y1, and z1 are the spatial coordinates of the radiotherapy target; x2, y2, and z2 are the spatial coordinates of the lesion.

[0051] In S5, the method for adjusting the spatial position of the treatment bed includes the following steps:

[0052] S501. Calculate the error vector from the radiotherapy target to the lesion point within the same spatial coordinate system;

[0053] S502. Perform a spatial coordinate transformation on the error vector to make its spatial coordinate system consistent with the spatial coordinate system within the treatment bed drive system.

[0054] S503. Adjust the position of the treatment bed according to the converted error vector.

[0055] The technical solutions described in this embodiment will be introduced below with reference to specific examples:

[0056] The treatment planning system obtained the three-dimensional coordinate information of the patient's radiotherapy target: X: 97.8mm; Y: 75.5mm; Z: 69.7mm. The imaging system scanned and reconstructed the lesion area to obtain the three-dimensional coordinate information of the lesion point: X: 102.4mm; Y: 65.3mm; Z: 77.7mm.

[0057] Since the spatial coordinate systems of the treatment planning system and the imaging system coincide, no spatial coordinate transformation is required, and this step can be skipped. The calculated spatial distance between the three-dimensional coordinate information of the radiotherapy target and the three-dimensional coordinate information of the lesion is 13.75 mm, which is greater than the error threshold of 5 mm, so the position of the treatment bed needs to be calibrated.

[0058] The error vector between the three-dimensional coordinates of the radiotherapy target and the three-dimensional coordinates of the lesion is (-4.6, 10.2, 8); in the coordinate system of the treatment planning system:

[0059] X-axis: Left and right direction, positive to the left and negative to the right;

[0060] Y-axis: vertical direction, downward is positive, upward is negative;

[0061] Z-axis: Head-to-foot direction, positive towards the head, negative towards the feet.

[0062] In the coordinate system of the treatment bed:

[0063] X-axis: Left and right direction, negative to the left, positive to the right;

[0064] Y-axis: vertical direction, downward is positive, upward is negative;

[0065] Z-axis: Head-to-foot direction, positive towards the head, negative towards the feet.

[0066] Therefore, the error vector needs to be transformed into coordinates. The transformed error vector is (4.6, 10.2, 8), and the treatment bed will automatically adjust according to the transformed error vector.

[0067] After adjustment, the lesion area was scanned and reconstructed in three dimensions using an imaging system. The new three-dimensional coordinate information of the lesion point was obtained as follows: X: 97.5mm; Y: 75.4mm; Z: 69.5mm. The spatial distance between the three-dimensional coordinate information of the radiotherapy target point and the three-dimensional coordinate information of the lesion point was calculated to be 0.14mm, which is less than the error threshold of 5mm and meets the accuracy requirements. Therefore, there is no need to adjust the position of the treatment bed.

[0068] Example 2:

[0069] This invention provides a radiotherapy positioning device, which employs a radiotherapy positioning method described in Embodiment 1. The device includes a treatment planning system, an imaging system, a treatment bed drive system, and a hardware board. The hardware board is used to acquire and decrypt the three-dimensional coordinate information of the radiotherapy target in the treatment planning system, acquire the three-dimensional coordinate information of the lesion in the imaging system, convert the three-dimensional coordinate information of the radiotherapy target and / or the three-dimensional coordinate information of the lesion into spatial coordinates, calculate the error distance, and send the error vector to the treatment bed drive system.

[0070] By setting up an independent hardware board, it is possible to obtain the three-dimensional coordinate information of the radiotherapy target from the treatment planning system of different models of Gamma Knife devices, and calculate the error distance based on the three-dimensional coordinate information of the lesion point in the imaging system. This then guides the treatment bed drive system, solving the problem that the data in the imaging system cannot be transmitted smoothly to the receiving interface of different models of Gamma Knife devices, which affects the efficiency of adjusting the position of the treatment bed.

Claims

1. A method for localizing radiation therapy, characterized in that: Includes the following steps: S1. Obtain the three-dimensional coordinate information of the radiotherapy target through the treatment planning system; S2. Scan and reconstruct the lesion area using an imaging system to obtain the three-dimensional coordinate information of the lesion point; S3. Perform spatial coordinate transformation on the three-dimensional coordinates of the radiotherapy target and / or the three-dimensional coordinates of the lesion, and place the radiotherapy target and the lesion in the same spatial coordinate system; S4. Calculate the error distance between the radiotherapy target and the lesion within the same spatial coordinate system; S5. When the error distance is greater than the error threshold, adjust the spatial position of the treatment bed and repeat steps S2-S4 until the error distance is less than the error threshold.

2. The radiotherapy positioning method according to claim 1, characterized in that: In S5, the method for adjusting the spatial position of the treatment bed includes the following steps: S501. Calculate the error vector from the radiotherapy target to the lesion point within the same spatial coordinate system; S502. Perform a spatial coordinate transformation on the error vector to make its spatial coordinate system consistent with the spatial coordinate system within the treatment bed drive system. S503. Adjust the position of the treatment bed according to the converted error vector.

3. The radiotherapy positioning method according to claim 1, characterized in that: S2 includes the following steps: S1. Simultaneously acquire images of the lesion area using at least two modalities of CBCT, kV-level X-ray, MRI, or ultrasound. S2. A cross-modal registration algorithm is used to register images of different modalities to the same coordinate system for three-dimensional reconstruction to obtain the three-dimensional coordinate information of the lesion.

4. The radiotherapy positioning method according to claim 1, characterized in that: S2 specifically includes: acquiring the patient's respiratory waveform and collecting the three-dimensional coordinate information of the lesion point at the end of expiration.

5. The radiotherapy positioning method according to claim 1, characterized in that: In S4, the error distance is calculated using the following method: In the formula, x1, y1, and z1 are the spatial coordinates of the radiotherapy target; x2, y2, and z2 are the spatial coordinates of the lesion.

6. The radiotherapy positioning method according to claim 1, characterized in that: In S4, the error threshold is 0.5 mm.

7. A radiotherapy positioning method according to claim 1, characterized in that: S1 specifically includes: identifying the encryption algorithm of the radiotherapy target three-dimensional coordinate information of the treatment planning system, and using the corresponding decryption algorithm to obtain the radiotherapy target three-dimensional coordinate information within the treatment planning system.

8. A radiotherapy positioning device, employing a radiotherapy positioning method as described in any one of claims 1-7, characterized in that: It includes a treatment planning system, an imaging system, a treatment bed drive system, and a hardware board. The hardware board is used to acquire and decrypt the three-dimensional coordinate information of the radiotherapy target in the treatment planning system, acquire the three-dimensional coordinate information of the lesion in the imaging system, convert the three-dimensional coordinate information of the radiotherapy target and / or the three-dimensional coordinate information of the lesion into spatial coordinates, calculate the error threshold, and send the error vector to the treatment bed drive system.

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