Dose-response relationship of radiation-induced pulmonary fibrosis in mouse models based on CT-derived parameters
Zhou Meijuan1, Zhou Zhaoming1, Wen Lei2, Liu Hao1, Cao Liji3, Lu Shun4, Li Ziyao5, Hui Zhouguang6, Cai Linbo2, Chen Ming7, Chen Longhua8, Zhou Cheng8
1Department of Radiation Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China; 2Department of Oncology, Guangdong Sanjiu Brain Hospital, Guangzhou 510510, China;3Inviscan SAS, France Strasbourg 67200; 4Department of Radiation Oncology, Sichuan Cancer Hospital & Institute, University of Electronic Science and Technology of China, Chengdu 610041,China; 5Department of Urology, First Affiliated Hospital of Dalian Medical University, Dalian 116011,China; 6Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing 100021, China; 7Zhejiang Key Lab of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou 310022,China; 8Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515,China
Objective To investigate the radiation induced pulmonary fibrosis with a dose-response mouse model, based on the CT image changes of pulmonary fibrosis.Methods Female C57BL6 mice aged 8-10 weeks were randomly divided into 20 Gy or escalated doses of X-ray whole thoracic irradiation (WTI) groups.CT scan was performed at different time points before and after radiation. The average lung density and lung volume changes were obtained by three-dimensional segmentation algorithm. After gene chip and pathological validation,the parameters of CT scan were subject to the establishment of logistic regression model. Results At the endpoint of 24 weeks post-irradiation,the lung density in the 20 Gy irradiation group was (-289.81±12.06) HU,significantly increased compared with (-377.97±6.24) HU in the control group (P<0.001). The lung volume was (0.66±0.01) cm3 in the control group,significantly larger than (0.44±0.03) cm3 in the irradiated mice (P<0.001). The results of quantitative imaging analysis were in accordance with the findings of HE and Mason staining,which were positively correlated with the fibrosis-related biomarkers at the transcriptional level (all R2=0.75,all P<0.001). The ED50 for increased lung density was found to be (13.64±0.14) Gy (R2=0.99,P<0.001) and (16.17±4.36) Gy (R2=0.89,P<0.001) for decreased lung volume according to the logistic regression model. Conclusions Quantitative CT measurement of lung density and volume are reliable imaging parameters to evaluate the degree of radiation-induced pulmonary fibrosis in mouse models. The dose-response mouse models with pulmonary fibrosis changes can provide experimental basis for comparative analysis of high-dose hypofractioned irradiation-and half-lung irradiation-induced pulmonary fibrosis.
Zhou Meijuan,Zhou Zhaoming,Wen Lei et al. Dose-response relationship of radiation-induced pulmonary fibrosis in mouse models based on CT-derived parameters[J]. Chinese Journal of Radiation Oncology, 2019, 28(8): 601-605.