Authors: Bao Wan, Bin Liang, Fukui Huan, Fengyu Lu, Wenbo Zhang, Yu Zhao, Tianhang Hong, Boyu Yang, Tantan Li, DongFu Chen, Qinfu Feng, Zefeng Xiao, Jima Lv, Nan Bi, Zongmei Zhou, Xin Feng^∗, Wenyang Liu^∗

Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China

Abstract: 
Performance of thoracic radiotherapy may be assisted by the use of thoracoabdominal flat immobilization devices (TAFIDs) and integrated cervicothoracic immobilization devices (ICTIDs). This study was per- formed to compare setup errors of TAFIDs and ICTIDs. Forty-four patients with lung cancer were retrospectively reviewed; 22 patients were immobilized with a TAFID and 22 with an ICTID. In total, 343 cone-beam computed tomography images of these patients were collected for radiotherapy setup. The 3-dimensional setup errors and the displacement of the acromioclavicular joint against the supraclavicular region were calculated. An independent-samples t-test and rank-sum test were used for statistical analyses. The translational setup errors of the TAFID group vs ICTID group in the left–right (LR), superior– inferior (SI), and anterior–posterior (AP) directions were 0.14 ± 0.17 vs 0.14 ± 0.16 cm (p = 0.364), 0.23 ± 0.26 vs 0.15 ± 0.15 cm (p = 0.000), and 0.16 ± 0.15 vs 0.12 ± 0.14 cm (p = 0.049), respectively. The relative displacement of the acromioclavicular joint against the supraclavicular joint in the LR, SI, and AP directions were 0.10 ± 0.12 vs 0.09 ± 0.10 cm (p = 0.176), 0.13 ± 0.13 vs 0.11 ± 0.12 cm (p = 0.083), and 0.17 ± 0.16 vs 0.12 ± 0.11 cm (p = 0.001), respectively. The overall displacement of the supraclavicular region was 0.28 ± 0.19 vs 0.23 ± 0.15 cm (p < 0.001). The recommended planning target volume margins in the LR, SI, and AP directions were 0.46 vs 0.74 cm, 0.51 vs 0.47 cm, and 0.49 vs 0.41 cm, respectively. For patients with lung cancer, using an ICTID can reduce setup errors in the SI direction and displacements of the acromioclavicular joint and supraclavicular region compared with a TAFID. Therefore, an ICTID is preferred for patients with lung cancer with supraclavicular target volume.

As of January 1, 2022, ARRT requires CE Credits for Directed Journal Readings to be based on the word count for each article. So, the number of CE Credits for each DJR article will vary for ARRT. For this article, the ARRT CE Credit will be 1 Credit. The MDCB CE Credits will remain at 2.5 Credits.

ARRT CQR Credit Distribution
Proton Therapy 2019
Procedures
Treatments = .75 credits
Radiation Therapy 2017
Procedures
Treatments = .75 credits
Radiation Therapy 2022
Procedures
Treatments = .75 credits