ObjectiveTo study the dose distribution of the intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) inverse plans with different energy X-ray, to provide a reference of energy options for radiation therapy. MethodsEight cases with different disease were chosen, the plan for each case were finished with 1Arc (360°) VMAT, 9 fields IMRT and 5 fields IMRT.For each plan project, the energy selections were 4 MV, 6 MV, 8 MV and 15 MV. In the evaluation,homogeneity index ( HI), conformity index ( CI ) and external volume index ( EVI ) of target, the average dose ( Dmean) and 2％ volume in dose volume histogram ( D2 ) of serial organs at risk ( OARs), the average dose ( Dmean ) and a dose level volume ( Vx ) of parallel OARs were chosen and compared . Results Statistical analysis showed that: For the target, the result of HI were F=0. 13,0. 51,0. 09, P=0. 939,0.679,0.965,CI were F=0. 13,0.51,0.09,P=0.939,0.679,0.965, EVI were F=0. 15,0.31,0. 15,P =0. 930,0. 818,0. 931, respectively ; For the OARs of each patient, F ＜ 0. 20, P ＞ 0. 05. All results indicated there was little difference in option of energy for the same field p8roject. ConclusionsThe results indicate that the middle and low energy X-ray (6 MV or 8 MV) can satisfy the needs of IMRT and VMAT radiotherapy. Compared with middle and low energy, the high energy X-ray (15 MV ) showed little advantage in dose distribution.

Objective In this study,Protosappanin A,Caesalpinia Sappan L extract and Cisplatin were combined with radiotherapy in gastric cancer cell SGC-7901 to investigate whether the Protosappanin A could in-crease radiosensitivity( SER) in gastric cancer SGC-7901 cells. This will be medication to create new areas of in-novation in the future. Methods The cell proliferation of SGC-7901 cells was detected by MTT assay. The rela-tionship between the effect of the Protosappanin A on cell proliferation and the time of action was determined. Caesalpinia Sappan L extract and Cisplatin were as controls. The fitted cell survival curve and clonal formation as-says were used to determine the SER to analyze the sensitizative effect of Protosappanin A. Results Protosappa-nin A could inhibit the growth of SGC-7901 cells,and its inhibitory effect is relatively weak. Its cytotoxicity has a time-and concentration-dependent manner. Cellular morphological changes were observed accompanying with increased concentrations and time treatments of Protosappanin A. Clonal formation experiment showed that the Protosappanin A significantly increased the radiosensitivity of SGC-7901 cells when compared to the radioactive group. They showed a statistically difference. Conclusion The inhibitory effect of the Protosappanin A on SGC-7901 cells in a concentration and time-dependent manner. Protosappanin A combined radiotherapy can improve the radiosensitization of cells,both of which may have synergistic anti-tumor effect.

Lung cancer is one of the most common malignant tumors with poor prognosis in China, and most patients are diagnosed as advanced patients. Studies have shown that the microecological characteristics of lung cancer patients are different from healthy people, and the microorganisms of the respiratory tract can affect the occurrence and development of lung cancer through various mechanisms. In recent years, the study of the correlation between microbiome and disease has become another research hotspot following the Human Genome Project. However, at present, there are relatively few studies on the characteristics of lung cancer and respiratory microbiome. Therefore, it is necessary to further explore the potential relationship between lung cancer and microbial flora. By studying the mechanism of action of respiratory microorganisms in the development of lung cancer, it is expected to provide a clearer scientific basis in the clinical diagnosis, treatment and prognosis assessment of lung cancer. This article reviews the current researches on microbial flora and lung cancer, and provides new ideas for clinical diagnosis and treatment of lung cancer.
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