The Influence Of SBHFRT And CFRT Techniques On Lymphocytes And Cytokines In Non-small Cell Lung Cancer

objective:Lung cancer is the most common malignacy at present.Radiotherapy is an important treatment for lung cancer.In addition to killing tumor cells directly,radiotherapy can also stimulate the anti-tumor immune response,promote the infiltration of anti-tumor lymphocytes and cytokines into tumor tissues,improve the tumor microenvironment,make tumors be more sensitive to the attack of the immune system,and enhance the therapeutic effect of tumors.Brachytherapy is more and more widely used in the treatment of lung cancer,but its effect on lymphocyte and cytokine in lung cancer tissue is not clear at present.The main purpose of this study was to investigate the influence of single brachytherapy hypofractionated radiotherapy（SBHFRT）and conventional fractionation radiotherapy（CFRT）on lymphocytes and cytokines in Non-small cell lung cancer（NSCLC）.Methods:Lewis cells were inoculated into the right hind leg of C57BL/6 mice to establish a transplanted model of non-small cell lung cancer,then the mice were randomly divided into a Control group,a conventional fractionation radiotherapy（CFRT）group and a single brachytherapy hypofractionated radiotherapy（SBHFRT）group.The tumor final volume of mice in each group and tumor growth inhibition rate（TGIR）of treatment groups were calculated on the 14th day after the end of treatment.At the 7 day and 14 day after the end of treatment,The necrosis rate of tumors was calculated by slice scanner and image analysis system.The apoptotic rate of cancer cells was detected by flow cytometry,the Immunohistochemistry method was used to detect the number of CD86、CD4、CD8、FoxP3 cells and the expression of Ki-67 in tumor tissues of the mice in each group,and the content of interleukin-10（IL-10）,interleukin-12（IL-12）and interferon-γ（INF-γ）in tumor tissues were measured by enzyme-linked immunosorbent assay（ELISA）.In order to evaluate the metabolic activity of tumor,18F-FDG microPET-CT was used to detect the maximum standardized uptake value（SUVmax）of tumors.Results:The experimental results showed that after 26days of tumor volume observation,the final volume of the tumors of the SBHFRT group was significantly lower than that of the CFRT group and the Control group（P<0.05）.On the 7th and 14th day after the end of treatment,the rate of tumor necrosis and the rate of tumor apoptosis in the SBHFRT group were higher than those of the CFRT group and the Control group（P<0.05）,while the expression of Ki-67 was lower than those of the CFRT group and the Control group（P<0.05）.On the 7th day after the end of treatment,CD86,CD4and CD8 cells in the SBHFRT group were higher than those of the CFRT group and the Control group（P<0.05）,while Foxp3 cells were lower than those of the CFRT group and the Control group（P<0.05）.On the 14th day after the end of treatment,CD86,CD4 and CD8 cells in the SBHFRT group were higher than those of the CFRT group and the Control group（P<0.05）,while Foxp3 cells were lower than those of the CFRT group and the Control group（P<0.05）.On the 14th day after the end of treatment,CD4 and CD8 cells in the SBHFRT group were less than those of the SBHFRT on the 7th day after the end of treatment（P<0.05）.On the 7th day after the end of treatment,the content of IL-12 and INF-gamma in the SBHFRT group were higher than those of the CFRT group and the Control group（P<0.05）,while the content of IL-10 were lower than those of the CFRT group and the Control group（P<0.05）.On the14th day after the end of treatment,the content of IL-12 and INF-gamma in the SBHFRT group were higher than those of the CFRT group and the Control group（P<0.05）,while the content of IL-10 in the SBHFRT group were lower than those of the CFRT group and the Control group（P<0.05）.On the 14th day after the end of treatment,the content of IL-12 and INF-gamma in the SBHFRT group were lower than those of the SBHFRT on the 7th day after the end of treatment（P<0.05）.On the 7th day after the end of treatment,the SUV_maxax value in the SBHFRT grouP was lower than those of the CFRT group and the Control group（P<0.05）.On the 14th day after the end of treatment,the SUV_max value in the SBHFRT group was lower than those of the CFRT group and the Control group（P<0.05）.On the 14th day after the end of treatment,the SUV_max value in the SBHFRT group was higher than those of the SBHFRT on the 7th day after the end of treatment（P<0.05）.Conclusion:1.The Infiltration of immune-related lymphocytes and cytokines in NSCLC is influenced by the radiotherapy technology and the dose of radiotherapy.The content of immune-related lymphocytes and cytokines in the SBHFRT group was significantly higher than those of the CFRT group.The SBHFRT technique improve the immune microenvironment of NSCLC more effecially when compared with CFRT technique.2.The necrosis and apoptosis that induced by SBHFRT were significantly higher than those induced by CFRT,and the inhibitory effect of the SBHFRT on NSCLC is better than that of the CFRT.3.This phenomenon that SBHFRT increase the content of immune-related lymPhocytes and cytokines in tumor tissues may be attributed to the fact that SBHFRT causes necrosis and apoptosis of tumors and inhibits tumor proliferation.