Comparison of postural errors of different immobilization methods in treatment with Cyberknife for intracranial tumors
10.3969/j.issn.1672-8270.2025.10.002
- VernacularTitle:不同固定方式在颅内肿瘤射波刀治疗中体位误差比较
- Author:
Hongming LI
1
;
Tingtian PANG
1
;
Yue ZHANG
1
;
Yuliang SUN
1
;
Lang YU
1
;
Xiansong SUN
1
;
Jie QIU
1
Author Information
1. 中国医学科学院北京协和医院放射治疗科 北京 100730
- Publication Type:Journal Article
- Keywords:
Cyberknife;
Intracranial tumor;
Six-dimensional skull(6D-skull)tracking;
Postural error
- From:
China Medical Equipment
2025;22(10):11-14
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the immobilization effect of two different immobilization methods in treatment with CyberKnife for intracranial tumors.Methods:A retrospective analysis was conducted on 48 patients with intracranial tumors who received treatment with CyberKnife in the Department of Radiotherapy at Peking Union Medical College Hospital from June 2023 to July 2024.Based on the different immobilization method,patients were divided into two groups:the Double Shell Positioning System(DSPS)group(n=22)and the Qfix group(n=26).The DSPS group was immobilized using an American full-body integrated positioning frame combined with a carbon fiber bracket and DSPS film,while the Qfix group was immobilized using an Encompass board and Qfix film.All patients were treated with 6 dimensions(6D)-skull tracking technique.During treatment,images were acquired as one times per 60 seconds,which were registered with digitally reconstructed radiograph(DRR)to record and compare the overall relative errors.The data of relative displacement error during treatment was calculated as|dx|=d1-d0,and differences between the two groups were compared.The maximum displacement(|d|=dmax-dmin)was also calculated,and difference in maximum displacement between the two kinds of immobilization methods was analyzed.Results:In the comparison of the overall relative errors between the two kinds of immobilization methods,the median values in the errors of superior-inferior(SI),anterior-posterior(AP),Roll,Pitch,and Yaw directions in the Qfix group were respectively 0.174,0.309,0.150,0.147,and 0.477,which were significantly less than those(0.224,0.316,0.175,0.221,and 0.584)of DSPS group,and the differences were statistically significant(Z=-4.358,-1.698,-2.595,-6.833,-5.371,P<0.05).The difference of the relative displacement errors between two kinds of immobilization methods was not significant(P>0.05),while the median values in all directions were not zero.The comparison of the maximum displacement value between the two kinds of immobilization methods indicated the displacement amounts of Qfix group was less than those of DSPS group on SI,left-right(LR),AP,roll,pitch,and yaw directions,and the differences of them were significant(Z=-3.373,-2.525,-2.488,-3.169,-5.130,-5.166,P<0.05).Conclusion:Both immobilization methods can meet the requirements of clinical treatment.The results of comparison indicate the immobilization effect of Qfix group is best,and the combination of Encompass board and Qfix film is recommended as the immobilization method of CyberKnife-based radiotherapy for intracranial tumors.
