The Effect of Four Dimensional CT on the Radiation Dose of Normal Tissues in Lung Cancer Patients with Stereotactic Radiotherapy
Objective To investigate the effect of four dimensional CT(4DCT)on the radiation dose of normal tissues in patients with stereotactic radiotherapy for lung cancer.Methods With the retrospective analysis of clinical data from 32 lung cancer patients with stereotactic radiotherapy in hospitals from February 2020 to November 2023,and the design of image-guided radiotherapy(IGRT)plans and non image-guided intensity modulated radiation therapy(IMRT)plans,among them,4DCT was adopted in the design of the IGRT plan.On the premise of meeting the prescription dose requirements for the target area,the errors in the head and foot,front and back,left and right directions of the two plans,as well as the normal tissue exposure doses(esophageal Dmean,spinal cord Dmean,spinal cord Dmax,cardiac Dmean and lung V5,V10,V20,Dmean)in end-inspiratory and end-expiratory images of the original plan,IGRT plan and IMRT plan,and the correlation between the radiation dose of normal tissue and the errors of head and foot,front and back,left and right direction were compared.In addition,the error values of two plans in different directions and their effects on the radiation dose for normal tissues such as esophagus,spinal cord,heart,and lungs were compared.Results The errors of head and foot,front and back,and left and right directions in the IGRT plan were(1.32±0.25)mm,(0.68±0.11)mm,and(0.41±0.10)mm,respectively,all lower than the IMRT plan's(5.46±2.31)mm,(2.65±0.32)mm,and(1.79±0.32)mm,with statistically significant differences(P<0.05).There were no significant differences between esophageal Dmean,spinal cord Dmean,spinal cord Dmax,cardiac Dmean and pulmonary V5 in end-inspiratory and end-expiratory images of original plan,IGRT plan and IMRT plan(P>0.05).The lung V10,V20,and Dmean of the end-inspiratory and end-expiratory images of the original plan and IGRT plan were significantly lower than those of the IMRT plan(P<0.05).There were no significant differences in lung V10,V20,and Dmean between the original plan and IGRT plan at the end of inspiratory and end expiratory images(P>0.05).The results of Pearson correlation analysis showed that the esophageal Dmean,spinal cord Dmean,spinal cord Dmax and heart Dmean of the images at the end of inspiratory and expiratory periods were only positively correlated with the head and foot direction error(P<0.05).The V5,V10,V20,and Dmean of the lung in end-inspiration and end-expiration images were positively correlated with the errors in head and foot,front and back,and left and right directions(P<0.05).Conclusion 4DCT can accurately evaluate the displacement of lung cancer lesions with respiratory movement,reduce the radiation dose of normal tissues in patients with stereotactic radiotherapy,reduce errors,and provide quality assurance for alleviating adverse reactions of radiotherapy.
Four dimensional CTLung cancerStereotactic radiotherapyErrorRadiation dose
万方数据
维普
