Effect of respiratory motion on radiation dose to the margin of target volume in stereotactic body radiotherapy for lung cancer
10.3760/cma.j.issn.1004-4221.2017.12.015
- VernacularTitle:呼吸运动对肺癌立体定向放疗靶区边缘剂量的影响
- Author:
Lingling TIAN
1
;
Ronghu MAO
;
Dingjie LI
;
Chengliang YANG
;
Lijie JIA
;
Hong GE
Author Information
1. 河南省肿瘤医院放疗科
- Keywords:
Lung neoplasms;
Radiotherapy dosage;
Respiratory physiological phenomena;
Microscopic disease;
Inadvertent irradiation dose
- From:
Chinese Journal of Radiation Oncology
2017;26(12):1426-1429
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of respiratory motion on inadvertent irradiation dose (ⅡD)to the microscopic disease(MD)and expanding margin of target volume in stereotactic body radiotherapy for lung cancer. Methods Based on the pattern of respiration-induced tumor motion during lung radiotherapy, a probability model of MD entry into or exit from internal target volume(ITV)was established and the theoretical dose to MD was calculated according to the static dose distribution by four-dimensional computed tomography. The experimental dose to MD during respiratory motion was measured using a respiration simulation phantom and optically stimulated luminescence(OSL)and then compared with the theoretical value for model validation.Results For the target volume in periodic motion,the deviation of the theoretical dose to MD from the experimental value measured by OSL was less than 5%. A 10-mm margin around ITV received a biological dose higher than 80 Gy. Conclusions The dose model established in this study can accurately predict the irradiation dose to MD in the target volume in periodic motion. Respiratory motion increases ⅡD to MD and there is no need to expand clinical target volume.
