부산대학교 도서관

During COVID-19 pandemic, the risk of infection transmission will increase, especially for patients with head and neck cancer. This study evaluated the feasibility of using thermoplastic masks with surgical masks for radiotherapy for patients with head and neck cancer. 2D-kV OBI images were acquired on 39 head-and-neck patients undergoing volumetric modulated arc therapy (VMAT), and divided into four groups based on different fixation patterns (two types head support head with and without wearing medical mask). Setup correction the mean displacement (M) , systematic (Σ), random variation (σ), 3D vector were analyzed after automatic image registration. The Independent Sample t test was used to analyze whether there is a difference in the set up error. There was a significant difference of shift between two groups (p ＜0.05). In the B-type headrest group, the measured average displacements of X, Y, Z, rot. , and pitch are 1.3 mm, 2.0 mm, 2.3 mm, 0.61°, 0.90° and 1.5 mm, 2.0 mm, 1.8 mm, 0.67°, 0.50° for B-type headrest without mask and with mask, respectively, and the absolute values of the errors on the Z (p＜0.003) and pitch (p＜0.001) are significantly different. The five-axis measurement of C-type headrest without mask and with mask the average displacement is 1.5 mm, 2.1 mm, 2.2 mm, 0.63°, 0.66° and 1.5 mm, 1.6 mm, 1.7 mm, 0.58°, 0.55° respectively. On the Y (p＜0.001), Z (p＜0.003) the absolute value of the error between the axis and the pitch ( p＜0.044 ) is significantly different, and the average displacement of each axis is in line with clinical specifications. The systematic and random errors of the X, Y, Z and rot. and pitch of the four types of fixation patterns are all less than 3mm and 0.70°. Therefore, during COVID-19 pandemic, patients will be treated with a surgical mask to cover the nose and mouth, which will improve the protection of patients and medical staff, and will not affect the accuracy of treatment.