Analysis of positioning errors in head and neck cancers during radiotherapy assisted by the 6D treatment couch and image-guided radiation therapy
10.19723/j.issn.1671-167X.2024.06.024
- VernacularTitle:6D治疗床辅助影像引导下放射治疗头颈部肿瘤摆位误差分析
- Author:
Suqing TIAN
1
;
Haitao SUN
1
;
Tiandi ZHAO
1
;
Wei WANG
1
Author Information
1. 北京大学第三医院肿瘤放疗科,北京 100191
- Publication Type:Journal Article
- Keywords:
Radiation therapy;
Head and neck tumors;
Image guidance;
Positional error;
Six-dimen-sional couch
- From:
Journal of Peking University(Health Sciences)
2024;56(6):1097-1100
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the intra-fraction and inter-fraction positional deviations in head and neck tumor patients undergoing intensity-modulated radiation therapy(IMRT)guided by cone-beam CT(CBCT),as well as the correction capability and stability of the HexaPOD evo RT 6D couch in addressing these deviations.Methods:From May 2019 to April 2022,59 consecutive patients with head and neck tumors were enrolled at the Department of Radiation Oncology,Peking University Third Hospi-tal.Using the Elekta AXESSE image-guided stereotactic treatment system,a pre-treatment CBCT scan was performed,followed by bone window mode registration with the planning reference images.Devia-tions were corrected automatically or manually on the 6D couch,followed by a second CBCT scan for con-firmation of the deviation correction.Positional errors in translation(X,Y,Z directions)and rotation(Rx,Ry,Rz directions)were recorded before and after correction,and intra-fraction and inter-fraction positional errors were analyzed.Results:Positional error data before and after correction of the 6D couch were successfully obtained and corrected online in 506 CBCT scans.The maximum positional errors be-fore and after correction were 0.90 cm to 0.04 cm(X direction),1.74 cm to 0.09 cm(Y direction),1.80 cm to 0.09 cm(Z direction),and 2.90° to 0.14°(Rx direction),3.00° to 0.15°(Ry direc-tion),3.00° to 0.15°(Rz direction),respectively.The mean absolute values of translational(X,Y,Z directions)and rotational(Rx,Ry,Rz directions)errors significantly decreased after online correction,from 0.18 cm,0.22 cm,0.25 cm,and 0.82°,1.11°,0.73° to 0.01 cm,0.01 cm,0.01 cm,and 0.04°,0.06°,0.04°(all P values＜0.001).After correction,the frequencies of translational errors less than 0.10 cm in the X,Y,Z directions were 99.60％,98.62％,and 95.45％,respectively,and the frequencies of rotational errors less than 0.2° were all above 99.80％.Conclusion:Online correc-tion combined with CBCT and the 6D couch significantly reduces both translational and rotational posi-tional errors in patients undergoing head and neck radiation therapy,greatly enhancing the precision of treatment.
