CBCT引导下放疗摆位误差校正对肺癌患者靶区覆盖率和正常组织保护的影响分析OA

Objective:To investigate the effect of cone beam CT(CBCT)guided combined with six dimensional treatment bed positioning error correction on the radiation target coverage and normal tissue protection of lung cancer patients.Method:80 lung cancer patients who received radical radiotherapy in the Quanzhou First Hospital from June 2024 to June 2025 were selected as the research subjects and divided into a control group(23EX three-dimensional treatment bed,n=40)and an observation group(Truebeam six dimensional treatment bed,n=40).The positioning errors,target area coverage(PTV D95%),normal tissue dosimetric parameters(bilateral lung V20,V5,spinal cord Dmax),and positioning time were compared between two groups.Result:The three-dimensional translation and rotation direction positioning errors in the observation group were significantly lower than those in the control group,with statistically significant differences(P<0.05).After treatment,the PTV D95%of the observation group was higher than that of the control group.The observation group had lower V20,V5 and spinal cord Dmax in both lungs compared to the control group.The average positioning time of the observation group was 1.6 minutes longer than that of the control group,the above differences all have statistical significance(P<0.05).Conclusion:CBCT guided six dimensional treatment bed positioning error correction can significantly improve the geometric accuracy and target area coverage of lung cancer radiotherapy,effectively reduce the dose to normal tissues such as the lungs and spinal cord,and enhance the safety and dose consistency of radiotherapy.Although its positioning time is slightly longer than traditional 3D correction,it has strong clinical operability and high repeatability,and is worthy of promotion and application in precision radiotherapy for lung cancer.