ABSTRACT
Objective To investigate influence of laser positioning system to position repeatability of patients treated with radiotherapy for pelvic tumors.Methods Forty patients with pelvic tumors were divided into two groups,using laser positioning system positioning (20 cases) and conventional positioning (20 cases),respectively,CBCT was used to verify and analyze the setup errors of two groups.Results The setup errors on X,Y and Z axes in laser positioning system positioning group were (2.63±1.07) mm,(2.38±1.28) mm and (2.46±1.21) mm,they were (3.04±1.22) mm,(2.55±1.35) mm and (3.09±1.37) mm in conventional positioning group.It has significance reduce on X and Z axes (P =0.040,0.003,respectively) by using laser positioning system,and has no significance on Y axis (P =0.432).Conclusion It can improve patient positioning repeatability effectively by using laser positioning system for patient positioning.