Normal lung tissue response following hypofractionated radiation based on radiological parameters
10.3760/cma.j.issn.0254-5098.2019.09.001
- VernacularTitle: 正常肺组织大分割照射全肺平均耐受剂量与生物学效应研究
- Author:
Cheng ZHOU
1
;
Runye WU
2
;
Zhaoming ZHOU
3
;
Wei FENG
1
;
Yujin XU
1
;
Jin WANG
1
;
Peng ZHANG
1
;
Lei SHI
4
;
Yuanyuan CHEN
1
;
Ming CHEN
1
Author Information
1. Zhejiang Key Lab of Radiation Oncology, Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou 310022, China
2. Department of Radiation Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
3. Department of Radiation Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
4. Department of Radiology, Zhejiang Cancer Hospital, Hangzhou 310022, China
- Publication Type:Journal Article
- Keywords:
Radiation fractionation;
Radiation induced lung fibrosis;
Boltzmann model;
Radiobiological modeling
- From:
Chinese Journal of Radiological Medicine and Protection
2019;39(9):641-646
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study dose-response relationships of fractionated irradiation induced pulmonary fibrosis in mice according to radiological imaging changes of lung.
Methods:A total of 8-10 week old-female C57BL6 mice were randomized into different groups for whole thoracic irradiation. The prescribed doses were 0, 2.0, 4.0, 6.0, 7.0, 8.5 Gy per fraction in a total of 5 fractions. CT imaging was performed at 24 weeks post irradiation. The averaged lung density and volume changes were obtained by the three-dimensional segmentation algorithm, and further analyzed in Boltzmann regression modeling.
Results:At the endpoint of 24 weeks, the dose-dependent pulmonary radiological alternations were revealed by coronal view of CT images. Translational analysis of fibrosis-related gene-signatures as well as histological collagen stainings further corroborated the radiological findings. According to Boltzmann modeling, the E50 of radiation-induced lung density changes was found to be (30.80±0.80)Gy (adjusted R2=0.97); whereas the E50 for radiation-induced lung volume reduction was determined as (31.31±7.07)Gy (adjusted R2=0.92). Both outcomes indicated a remarkable enhancement of tolerance to normal lung tissues after exposure with 5-fraction versus single fraction scheme.
Conclusions:The radiation-induced lung density and volume changes depend not only on total dose, but also the number and dose of fractions.
