Analysis of setup errors in patients using the customized Klarity AccuCushion® with a thermoplastic fixation mask while receiving radiotherapy / 中国肿瘤临床

ABSTRACT

Objective: To compare setup errors between patients using the customized Klarity AccuCushion® with a thermoplastic fixation mask and patients using a thermoplastic fixation mask or vacuum fixation cushion alone while receiving radiotherapy. Methods: A total of 66 patients with head and neck (H&N) tumors (n=27) or thoracic and abdominal tumors (T&N) tumors (n=39) were included during Jaurnary 2018 to December 2019. 15 H&N cancer patients using only a single head-neck-shoulder mask were categorized into group A; 12 patients using a customized Klarity AccuCushion® and head-neck-shoulder mask were categorized into group B. Among T&A cancer patients, 19 patients using only a vacuum fixation cushion were classified into group A; the remaining 20 patients using a customized Klarity AccuCushion® and thermoplastic fixation mask were classified into group B. Cone-beam computed tomography was performed, and the setup errors were evaluated. The setup errors in the left-right (LR) direction, superior-inferior (SI) direction, anterior-posterior (AP) direction, and for rotation were compared between groups A and B. Results: Among H&N cancer patients, the setup errors in group B in the LR direction, SI direction, and for rotation were 0.06±0.06 cm, 0.08±0.07 cm, and 0.12±0.17°, respectively, which were smaller than those in group A (0.10±0.11 cm, 0.13±0.14 cm, and 0.25±0.47°, respectively). The differences in setup errors in the LR direction, SI direction, and for rotation were significant between the two groups (P0.05). For T&A cancer patients, significant differences were found in setup errors between the two groups (P<0.05) in the LR direction (group B vs. group A: 0.10±0.08 cm vs. 0.14±0.12 cm) and for rotation (group B vs. group A: 0.09 ± 0.18° vs. 0.22 ± 0.39°). No significant differences were observed in the setup errors in the SI and AP directions. Conclusions: Compared with the immobilization techniques using only a thermoplastic mask and only a vacuumed fixation cushion, the technique using a customized Klarity AccuCushion® with a thermoplastic fixation mask can improve repeatability, stability, and setup errors in radiotherapy.