Comparison of setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy of lung cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective@#To compare the setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy (SBRT) of lung cancer.@*Methods@#A total of 24 cases treated with SBRT were selected and all patients were fixed with vacuum pad in the supine position. Patients in group A were positioned by Catalyst HD and those in group B were positioned by shin markers. All patients were matched with the CT images after CBCT scan by rigid registration and the setup errors in six directions (x-, y-, z-axis, Rtn, Pitch and Roll) were obtained.@*Results@#The mean±SD in group A and B in the six directions were as follows (0.13±0.12) cm, (0.25± 0.19) cm; (0.26±0.15) cm, (0.13±0.11) cm; (0.23±0.19) cm, (0.35±0.29) cm; (0.43°±0.40°), (0.80°±0.69°); (0.48°±0.47°), (0.79°±0.64°); (0.62°±0.60°) and (0.88°±0.70°), respectively. Except the x-axis data in group B, all the data in the six directions were not normally distributed. The obtained data significantly differed between two groups (all P<0.05). The out-of-tolerance errors (>0.5 cm/2°) also significantly differed between two groups (P<0.05).@*Conclusions@#The setup errors of Catalyst HD are less than those of the skin markers (except the y-axis). The setup accuracy of Catalyst HD is superior to that of traditional skin markers, which is worthy of application in clinical practice.