Dose reconstruction method based on tumor motion tracking and radiotherapy

Abstract

The present invention relates to a 4D dose reconstruction device, and discloses a dose reconstruction method based on tumor motion tracking and radiotherapy, including: step S1, obtaining the tumor centroid motion core, and obtaining the tumor centroid in the LR direction, CC direction and AP direction Time function; step S2, obtain the motion parameters of the tumor center of mass according to the time function in the LR direction and the CC direction in step S1; step S3, control the driving module to drive the dose verification device LR and CC to move in two directions according to the motion parameters in step S2 , step S4, the influence of AP direction movement on the dose is realized by real-time online correction of the percentage depth dose PDD parameter method, and finally realizes the 4D dose reconstruction of the dose verification device and obtains the reconstructed 4D dose data. The introduction of the three-dimensional movement factor of the tumor in the present invention can effectively improve the radiotherapy plan of the tumor, make the final treatment of the patient closer to the actual situation, and greatly improve the safety and effectiveness of the radiotherapy of the tumor.

Description

technical field [0001] The present invention relates to a 4D dose reconstruction method, in particular to a dose reconstruction method based on tumor motion tracking and radiotherapy. Background technique [0002] Radiation therapy for lung cancer has achieved remarkable results in recent decades, but the low rate of local control is still the biggest problem. Surgery is the standard treatment for early lung cancer. Radiotherapy is the main treatment for patients with early lung cancer who cannot tolerate surgery or refuse surgery. The effect of conventional fractionated radiotherapy for early lung cancer is not good, and the 5-year survival rate of patients is 10-30%. Stereotactic body radiation therapy (SBRT) for early surgically unresectable lung cancer can obtain a relatively ideal local control probability and overall survival rate. However, because lung tumors are greatly affected by respiratory movement, especially for patients with small-volume tumors and large brea...

AI Technical Summary

Problems solved by technology

Neither the US nor the European studies have clarified the issue that "features extracted from static CT are the reference gold standard for extracting features from 4DCT images".

[0006] (2) In terms of research methods, the current research at home and abroad mainly uses one-dimensional motion phantoms to simulate the impact of breathing amplitude on 4DCT images and radiation therapy ITV, without considering the clinical real breathing motion

[0007] (3) Ignoring the differences in 4DCT scanning equipment and scanning parameter settings, 4DCT-based radiotherapy and dose verification must be based on the premise and basis of in-depth research on the influence of 4DCT images on respiratory motion and scanning parameter settings

[0008] (4) The preprocessing of 4DCT images is still in the preliminary exploration stage, and there is currently a lack of reliable conclusions for clinical use

[0011] 1. The essence of the patient's respiratory movement is the volume change of the thoracic cavity. The impact of this volume change on the tumor is mainly reflected in the three directions of LR, AP, and CC, and the two directions of LR and CC are the main directions, while the direction of AP affects The smallest, so the three directions will have an impact on the dose at the same time, the CN208808505U patent can only simulate that the patient's tumor is affected by respiratory movement in one direction, which is quite different from the actual situation

[0012] 2. The effect of the patient's respiratory movement on the position of the tumor is not linear, nor is it a regular trigonometric function waveform, and the movement of the center of mass of the tumor is not uniform. The CN208808505U patent can only simulate the patient's tumor linearly in one direction or according to the actual setting Good amplitude and frequency, which deviates greatly from the actual movement of the patient's tumor

[0013] 3. The CN208808505U patent can only simulate the influence of respiratory movement on the reconstruction of tumor organ doses when the accelerator treatment rack is at zero temperature. However, in the actual treatment of patients, it is not only a zero-degree radiation field, but it is necessary to consider avoiding important organs around the tumor. There are many non-zero radiation fields, and the non-zero radiation fields have a geometric projection effect on tumor dose reconstruction. For example, the original left and right LR direction movement becomes a problem of irradiation depth change when the actual irradiation gantry angle is 90° or 270° , which is also a difficult problem that has not been solved in 4D dose reconstruction

[0014] 4. CN208808505U patent can only roughly simulate the tumor movement of patients whose organ movement frequency is in a certain interval, the movement range is very uniform, and the repeatability of each breathing cycle is very good

The results can only be used for scientific research and cannot be given to each patient's specific dose analysis report, which has great limitations

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