Objective The objective of this study was to study the dosimetric characteristics and advantages of Non-coplanar IMRT techniques stereotactic body radiation therapy(SBRT)in the early stage of NSCLC.Methods Ten patients were selected with early stage of NSCLC.Treatment planning designed 9 fields coplanar IMRT and 9 fields Non-coplanar IMRT,respectively.Non-coplanar plans include five coplanar fields and four non-coplanar fields.Two group patients' plans compared V2.5,V5,V20,V25 of the whole lung,the average exposure doses of the whole lung,and the average exposure doses of the contralateral lung.The comparison of the other OARs include:spinal cord Dmax,heart Dmax,esophagus Dmax,trachea Dmax,chest wall Dmax and V30 of chest wall.At the meantime,we compared the conformal index of PTV(CI)and the homogenization index of PTV(HI).Results Non-coplanar plans reduced V20 of the whole lung(P=0.001),the average exposure dose of the contralateral lung(P=0.001),but V5 of the whole lung non-coplanar plans were increased than that in coplanar plans(P=0.002).Non-coplanar technology reduce max dose of spinal cord,esophagus,trachea,chest wall and V30 of chest wall(P=0.026,0.001,0.026,0.008,0.016).Heart Dmax of the non-coplanar plans was high in coplanar plans with no statistical significance difference(P=0.296).The conformal index of PTV of the non-coplanar plans was better(P=0.036),there was no difference in the homogenization index of PTV(P=0.254).Conclusion The stereotactic body radiation therapy of the early stage of NSCLC,the non-coplanar technology can effectively reduce exposure doses of the lung tissue and the other most OARs,also improve the conformal index of the PTV.The non-coplanar technology have possibility in reducing complications when compared with the coplanar technology and therefore has certain dosimetry advantage.

Long tracheal lesions are mainly caused by stenosis, infection, trauma, malignant tumors and other factors. Resection of the diseased tissue or stenosis and end-to-end anastomosis is currently the gold standard for long tracheal lesions treatment. However, these treatment programs have proven to have major limitations. In recent years, tissue engineering technology has been regarded as a promising medical alternative treatment method, and the selection of scaffold materials is one of key parts. With the continuous exploration of domestic and foreign researchers, biological materials have been continuously developed and applied to the research of tissue engineering trachea. Tissue engineering degradable scaffold materials can be divided into natural polymer material scaffolds and synthetic polymer scaffolds according to the different sources. The scaffold material can be modified or compounded as needed to improve the biological properties of scaffolds. In addition, with the continuous development of biological printing technology, different scaffold materials can be better combined and used. Biodegradable scaffolds have become a new research direction in the field of tissue engineering trachea due to their polymer properties, and have good application prospects.

Objective:To investigate the biocompatible properties of tissue-engineered rabbit trachea treated by Triton-X 100 processed method (TPM) and detergent enzymatic method (DEM) with genipin cross-linking.Methods:TPM and DEM were used to decellularize New Zealand rabbit trachea, and then genipin was used for cross-linking. The mechanical properties of each tracheal sample were measured by universal tensile testing machine. The structure of the sample was observed by scanning electron microscope. The cytotoxicity of the sample was detected by cell contact toxicity assay. Fifteen healthy adult New Zealand rabbits with no specific pathogens were divided into the native tracheal transplantation group, the genipin cross-linked TPM acellular tracheal matrix transplantation group and the genipin cross-linked DEM acellular tracheal matrix transplantation group according to the random number table, 5 animals for each group. Animals in each group were sacrificed 30 days after transplantation, and graft samples were obtained. The microstructure was observed by hematoxylin-eosin staining and CD68 molecular immunohistochemical staining.Results:Biomechanical results showed that the mechanical properties of decellularized tracheas with genipin cross-linking were similar to native tracheas. The results of scanning electron microscopy showed that the matrix of cross-linked decellularized tracheas was more dense comparing with native tracheas, and the mesh-like ultrastructure formed on the outer surface of the genipin cross-linked DEM acellular tracheal matrix was conducive to cell adhesion. The results of cell contact toxicity results showed that the genipin cross-linked decellularized tracheas treated by DEM had better biocompatibility. The results of in vivo implantation and histological staining showed that genipin cross-linked DEM acellular tracheal matrix was less immunogenic comparing with genipin cross-linked TPM acellular tracheal matrix.Conclusions:Genipin can improve the ultrastructure of decellularized tracheal matrix without causing inflammatory. The genipin cross-linked decellularized tracheas treated by DEM has better biocompatibility and lower immunogenicity, which make it suitable for the replacement of tissue engineering trachea.