Ionizing radiation has proved to be most valuable in clinical diagnosis and radiotherapy. And also it is used very common in industries especially such as industrial radiography, atomic energy plant, inspectoring by gamma-ray, etc. However, inadvertent exposure to relatively high doses of ionizing radiation is capable of injuring and killing cells. The lungs, because of their rich vascularization, are vulnerable to radiation injury. It is now known that IL-6 is a pleiotrophic cytokine produced by various cells that regulates the immune reponses, acute phage reactions. We performed the immunohistochemical staining of IL-6 on radiation induced lung injury by duration, to clarify the role of IL-6 in tissue damage. IL-6 was strongly expressed in early phase of radiation from alveolar macrophages and damaged endothelial cells. These findings not only have important implications for increasing our understanding of mechanisms of radiation lung injury but they also have an impact on strategies for diagnosis and therapy of radiation damage.
Bacteriophages ; Diagnosis ; Endothelial Cells ; Homicide ; Interleukin-6* ; Lung Injury ; Lung* ; Macrophages, Alveolar ; Nuclear Energy ; Plants ; Radiation Injuries ; Radiation, Ionizing ; Radiography ; Radiotherapy

OBJECTIVE: To determine the efficacy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the detection of radiation-induced myocardial damage in beagles by comparing two pre-scan preparation protocols as well as to determine the correlation between abnormal myocardial FDG uptake and pathological findings. MATERIALS AND METHODS: The anterior myocardium of 12 beagles received radiotherapy locally with a single X-ray dose of 20 Gy. 18F-FDG cardiac PET/CT was performed at baseline and 3 months after radiation. Twelve beagles underwent two protocols before PET/CT: 12 hours of fasting (12H-F), 12H-F followed by a high-fat diet (F-HFD). Regions of interest were drawn on the irradiation and the non-irradiation fields to obtain their maximal standardized uptake values (SUVmax). Then the ratio of the SUV of the irradiation to the non-irradiation fields (INR) was computed. Histopathological changes were identified by light and electron microscopy. RESULTS: Using the 12H-F protocol, the average INRs were 1.18 +/- 0.10 and 1.41 +/- 0.18 before and after irradiation, respectively (p = 0.021). Using the F-HFD protocol, the average INRs were 0.99 +/- 0.15 and 2.54 +/- 0.43, respectively (p < 0.001). High FDG uptake in irradiation field was detected in 33.3% (4/12) of 12H-F protocol and 83.3% (10/12) of F-HFD protocol in visual analysis, respectively (p = 0.031). The pathology of the irradiated myocardium showed obvious perivascular fibrosis and changes in mitochondrial vacuoles. CONCLUSION: High FDG uptake in an irradiated field may be related with radiation-induced myocardial damage resulting from microvascular damage and mitochondrial injury. An F-HFD preparation protocol used before obtaining PET/CT can improve the sensitivity of the detection of cardiotoxicity associated with radiotherapy.
Animals ; Dogs ; Fasting ; Fluorodeoxyglucose F18/*metabolism ; Heart/*radiography ; Heart Injuries/*radiography ; Male ; Myocardium/metabolism/pathology ; Positron-Emission Tomography/*methods ; Radiation Injuries/diagnosis/*radiography ; Thoracic Neoplasms/radiotherapy ; Tomography, X-Ray Computed/*methods