Effect of Surgical Mask in Head and Neck Cancer on Setup Error in Radiotherapy

Abstract

Background: With the widespread prevalence of Corona Virus Disease 2019 (COVID-19), cancer patients are suggested to wear a surgical mask during radiation to prevent disease for both patients and staff. Objective: The purpose of this study was to compare the setup error and KV image times taken for pre-radiation positioning for patients with head and neck irradiation between patients who wore a surgical mask plus a thermoplastic mask and those who did not a surgical mask was applied to a thermoplastic mask. Method: The setup errors in 3 directions of Vrt., Lng. and Lat. and KV-image times data were collected from 216 head and neck cancer patients with a surgical mask group with a thermoplastic mask and the patients without a surgical mask group with a thermoplastic mask who received radiation treatment with intensity modulated-radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) from varian Clinac IX and Vital beam in Radiotherapy department, Lopburi cancer center hospital during January 2020 to October 2021. The setup errors and KV-image times of patients were calculated. A t-test was performed to detect whether it was statistically significant. Results: The average of KV-image times to positioning setup before radiation therapy was longer than the patients without a surgical mask group with thermo plastic mask. There was no statistical difference (P=0.066). Average of setup errors in Vrt., Lng.and Lat.for patients irradiated with head and neck cancer were 0.19+0.09 cm.,0.23+0.11 cm. and 0.18+0.09 cm., respectively, in the group of patients wearing a surgical mask with thermoplastic mask and were 0.18+0.08 cm., 0.20+0.08 cm. And 0.16+0.66cm., respectively, in the group of patients who without a surgical mask with thermoplastic mask.A statistical comparison revealed that the pre-radiation positioning setup error for head and neck cancer patients with surgical mask and thermoplastic mask was not used with thermoplastic mask, most were not statistically different (P=0.617, 0.058) in Lng. and Lat., respectively, except in Vrt., they were statistically different (P=0.024). The PTV Margins in Vrt., Lng. and Lat. were 0.35, 0.40 and 0.28 cm., respectively, in the group of patients wearing a surgical mask with thermoplastic mask and were 0.30, 0.31 and 0.34 cm. respectively, in the group of patients who without a surgical mask with thermoplastic mask.Conclusion: The results of this study show that the addition of surgical mask and thermoplastic mask in patients irradiated with head and neck cancer affects the pre-radiation positioning error. The objectives of this research were to study for a guideline the prevention and control of the coronavirus disease 2019 (COVID-19).