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.