The Study Of Radiomics Applicated In Radiotherapy Of Thoracic Cancer Based On 4DCT

As one of the three major treatment of cancer,radiotherapy play an important role in all stages of cancer treatment.Radiotherapy kill tumor cells using X-rays,electron beams,proton beams,or other particle beams generated by accelerator to increase the rate of tumor control and survival of tumor patients.In theory,accurate radiotherapy should allow the target dose reach the prescribed dose,while other organs do not receive any dose for the purpose of killing tumors and protecting normal organs,which puts high requirements on the accuracy of radiotherapy.The main affect reason of accuracy radiotherapy is uninterrupted breathing movement of the lungs for thoracic cancer.Respiration can cause the changes of location,shape,size of tumor target and organs at risk during the treatment of patients with thoracic tumors,which lead to the leakage of tumor target dose and overdose of organs at risk,it is one of the main reason with the failure of regional tumor control and increased complications of radiotherapy.Four-dimensional computed tomography(4DCT)technology has become popular in accurate radiotherapy of thoracic tumors in recent years.4DCT is scanning in a stable and natural breathing state,so it can obtain the changes with lung tissue inflated state and airflow velocity at different respiratory nodes,which reflect the change of lung tissue and thoracic tumor with respiration truly.Radiomics can obtain prediction information of tumor prognosis based on clinically relevant treatment responses non-invasively by using high-throughput extraction and analysis of a large number of quantitative imaging features from medical images,which has a high clinical application value.The study of radiomics has become increasingly widespread in recent years with thoracic tumor,but the radiomics study accurate of thoracic tumor would be affect due to respiratory movements.The impact of respiratory motion on the extraction of image features has rarely been reported because of imaging technical and scanning equipment.In this paper,we explored the influence of respiratory motion on feature extraction using 4DCT to increase the accuracy of the study in radiomics for thoracic tumor.We found that respiratory movements have a greater impact on the local characteristics of lung tissue and may contribute to the study of lung function.We also focused on the deformation registration algorithm to obtain pulmonary ventilation images based on 4DCT,the lung ventilation images has been proved in using for assist patients with radiotherapy to reduce the incidence of radiotherapy pneumonia and other radiotherapy adverse reactions on the basis of previous study.Main contents in this paper are as follows:1.We introduced the current status of radiotherapy,expounded the basic concepts,scanning methods and principles of 4DCT,and research advances in medical image processing.2.We introduced the basic concepts,research procedures,and significant utilization value of CT-based imagery for the current research hotspots in detail,and elaborated the research process and significance of the 4DCT pulmonary ventilation images.3.To obtain the influence of radiomics feature extraction caused by respiration,the different phase of 4DCT were used to extract features,the R~2 method was used to screen the extracted features to reduce the redundancy of the data and explore the change of radiomic features for different phase using statistical method.4.We introduced the diffeomorphic Demons deformation registration algorithm in detail to obtained pulmonary ventilation images based on 4DCT,and present the current status of pulmonary ventilation function images in radiotherapy.5.We summed up the research of this paper and put forward further research directions in the future.