ABSTRACT
Objective:By comparing the positioning errors caused by 3D printed personalized breast bracket and common headrest in intensity-modulated radiation therapy (IMRT), the fixation effect of 3D printed personalized breast bracket in IMRT was analyzed.Methods:Thirty-two breast cancer patients from January to July 2021 were randomly divided into a the 3D printed breast bracket group and common headrest group. All patients in two groups were kept in supine position, head tilted to the healthy side, the affected hand held the grip bar on the same side of the horizontal bar, the healthy hand held the opposite side of the vertical bar, and the chest and mandible were fixed with thermoplastic film. CBCT scan was performed weekly, and gray level registration was carried out according to the three registration regions of interest: breast or chest wall field, supraclavicular and inferior field, and axillary field. The positioning errors in the left and right, head and foot, abdomen and back directions were analyzed between two groups.Results:In the 3D printed breast bracket group, the positioning errors of breast or chest wall field, supraclavicular and inferior field and axillary field in the left and right, head and foot, abdomen and back directions were (1.75±1.26), (1.77±1.11) and (1.70±1.08) mm, (1.75±1.25), (1.72±1.09) and (1.70±1.05) mm,(1.86±1.34), (2.14±2.13) and (1.66±1.19) mm, respectively.In the common headrest group, the positioning errors of breast or chest wall field, supraclavicular and inferior field and axillary field in the left and right, the head and feet, the abdomen and back directions were (2.54±1.84), (2.73±3.62) and (2.18±2.45) mm, (3.25±2.02), (3.52±2.26) and (2.62±2.83) mm, (3.25±2.05), (4.44±2.90) and (3.10±3.18) mm, respectively.The positioning errors significantly differed between two groups (all P<0.05). Conclusions:The positioning error of 3D printed personalized breast bracket fixation is less than that of common headrest fixation. The positioning consistency of 3D printed personalized breast bracket in the three target areas of breast or chest wall field, supraclavicular and inferior field and axillary field is better than that of common headrest.