Effects of immobilizations with head and neck mask or chest body covering on dose distribution in the radiotherapy for upper thoracic esophageal carcinoma(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2022年第2期
- Page:
- 157-161
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of immobilizations with head and neck mask or chest body covering on dose distribution in the radiotherapy for upper thoracic esophageal carcinoma
- Author(s):
- WANG Ying1; CHEN Fei2
- 1. Department of Oncology, West China Guangan Hospital, Sichuan University, Guangan 638001, China 2. Department of Pathology, West China Guangan Hospital, Sichuan University, Guangan 638001, China
- Keywords:
- Keywords: upper thoracic esophageal carcinoma radiotherapy body immobilization head and neck mask chest body covering three-dimensional treatment planning system dose distribution
- PACS:
- R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2022.02.005
- Abstract:
- Abstract: Objective To study the effects of immobilizations with head and neck mask or chest body covering on the dose distribution in the three-dimensional treatment planning system (TPS) radiotherapy for upper thoracic esophageal carcinoma (EC). Methods The clinical data of 128 patients with upper thoracic EC were retrospectively analyzed. The patients were divided into mask group (46 cases) and body covering group (82 cases) according to different body immobilization techniques. All patients were in the supine position and intervened with intensity-modulated radiotherapy. As for body immobilization techniques, thermoplastic head and neck mask was used in mask group, and thermoplastic body covering in body covering group. The setup errors, dose distribution, radiation dose to organs-at-risk, short-term efficacy and adverse reactions were compared between two groups. Results The absolute values of X-, Y- and Z-axial setup errors of mask group were significantly lower than those of body covering group (P<0.05) and compared with body covering group, mask group had a lower homogeneous index and a higher conformity index (P<0.05) and there were no significant differences in the Dmax, Dmin and Dmean to the target area between two groups (P>0.05). The V10, V20 and V30 of both lungs and the Dmean to spinal cord in mask group were all lower than those in body covering group, with statistical differences (P<0.05). The objective response rate was 58.70% in mask group and 54.88% in body covering group (P>0.05), and no significant difference was found in the short-term efficacy between two groups (P>0.05). The incidence rate of radiation pneumonitis in mask group was lower than that in body covering group (P<0.05). Conclusion Immobilization with head and neck mask for radiotherapy of upper thoracic EC can help to reduce setup errors, improve the homogeneity and conformity of TPS radiotherapy dose distribution, lower the radiation dose to the surrounding normal organs, and decrease the occurrence of radiotherapy-related adverse reactions.
Last Update: 2022-03-07