ABSTRACT
Objective:To investigate setup errors of two fixation methods of transparent head pillow and vacuum bag head pillow in patients with head and neck tumors when undergoing radiotherapy.Methods:A total of 40 patients with head and neck tumors undergoing radiotherapy admitted to Meizhou People's Hospital of Guangdong Province from January 2017 to December 2018 were selected and randomly divided into the control group (transparent head pillow fixation) and the research group (vacuum bag head pillow fixation), with 20 cases in each group. Kilovoltage cone-beam computed tomography (CBCT) was used to obtain the registration image data of each patient for 10 times during the linear accelerator treatment. The linear and rotational positioning errors of two groups were also analyzed.Results:The linear setup errors in the direction of left-right (X-axis), head-foot (Y-axis) and front-back (Z-axis) were (1.1±0.8) mm, (0.9±0.8) mm and (1.2±0.9) mm in the study group, and (1.3±1.1) mm, (1.1±1.1) mm and (1.4±1.1) mm in the control group. The rotation setup error of X-axis, Y-axis, Z-axis was (0.73±0.52) °, (1.08±0.89) ° and (0.89±0.74) °, respectively in the study group, and (0.81±0.69) °, (1.38±1.05) °, (0.88±0.70) °, respectively in the control group. The difference of linear setup error in Y-axis and Z-axis was statistically significant ( P = 0.016, P = 0.004). The difference of rotation setup error in X-axis and Y-axis was statistically significant ( P = 0.036, P = 0.001). Conclusion:The vacuum pillow is better than the transparent pillow in improving the rotation error and linear error for patients with head and neck tumors undergoing radiotherapy.