肺癌脑转移瘤立体定向放射治疗中两种不同体位固定方式误差分析OA

Objective:This study aimed to compare the precision differences between the individualized Fraxion patient positioning and fixation technique and the positioning and fixation technique combining a shaping pad with a thermoplastic film in stereotactic radiotherapy for brain metastases from lung cancer.Methods:A total of 39 patients with lung cancer brain metastases who met the indications for stereotactic cranial radiotherapy and were admitted to the Department of Radiation Oncology,Gansu Provincial Cancer Hospital from January to December 2024 were selected.The patients were randomly divided into two groups.Nineteen patients were fixed using the individualized Fraxion position-ing technique,while the remaining 20 patients were fixed with the combination of a shaping pad and a thermoplastic film.Two sets of setup error data were collected using an Elekta-infinity medical linear accelerator,and statistical analysis was conducted.Results:There were no statisti-cally significant differences in the three-dimensional translational errors and rotational errors between the two fixation methods.However,the overall setup errors in the Fraxion group were smaller:both the absolute translational errors and rotational errors were lower than those in the shaping pad group,and the expansion margin of the target volume in the Y-axis direction was significantly reduced.Conclusions:Both the in-dividualized Fraxion positioning and fixation technique and the shaping pad combined with thermoplastic film fixation technique can meet the requirements for target volume precision and repeatability in SRT for brain metastases from lung cancer,and thus have clinical application val-ue.Among them,the Fraxion positioning and fixation technique has greater advantages in controlling multi-dimensional translational errors and rotational errors,and can reduce the expansion margin of the target volume in the Y-axis direction,providing more support for improving treat-ment precision.