Objective To research the structure and principle of Helical Tomotherapy, and study the clinical application value of the equipment system. Methods As the first helical radiotherapy system in the mainland of China, its constructions, structure and principle were analyzed and discussed. Results Helical Tomotherapy is a new kind of radiotherapy equipment. The Hi-Art treatment system is a combination of a LINAC and a CT scanner capable of having the function of both systems. It was approved to achieve the best intensity modulated radiation therapy (IMRT), used for adjusting the setup position of the patient with MVCT and as the basis for dose reconstruction and other adaptive radiotherapy processes. It is the first integrated planning, delivery and verification system for IMRT. Conclusion Image-guided radiation therapy (IGRT) and IMRT have introduced a new era in radiation oncology which will better fight cancer and simultaneously improve the patients' quality of life. Having been designed from the ground up for IGRT and IMRT, the tomotherapy system is in the forefront of technical advancements for efficacy and processes to make it efficiently.

The finite element method was used for simulating the mechanical performance and fatigue safety of three different structures of Nitinol stent. According to the actual situation, after proposing reasonable assumptions and simplification, the geometry model and finite element model establishment, material mode selection and boundary condition setting are completed. The strain and fatigue life of different stent edges wide (omega) or strut angle (theta) are computed. The result can provide a valuable reference for the optimal design of stent.
Alloys ; Finite Element Analysis ; Prosthesis Design ; Stents

Objective　To evaluate the expression of Fas/FasL antigen on peripheral blood T lymphocytes and its possible role in Behcet disease. Methods　The expression of Fas and FasL antigen on peripheral blood T lymphocytes was determined by flow cytometry and three-colour double marked immunofluorescence methods in 26 patients with Behcet disease and 43 healthy individuals. Results　The difference was significant between Behcet disease (25.70%±7.32%) and controls (14.02%±6.30%) concerning the Fas expression on CD4+ T lymphocytes(P＜0.01) . But no difference was found concerning the expression of FasL antigen between Behcet disease and controls (P＞0.05).The expression of Fas antigen on CD8+ T lymphocytes from Behcet disease (9.47%±6.97%)was significantly higher than that in control group(3.47%±2.75%), but no difference was found concerning FasL antigen expression on CD8+ T lymphocytes between Behcet disease and controls(P＞0.05).Conclusion　These results indicate the imbalance of the expression of Fas and FasL on T lymphocytes in Behcet disease is responsible for the perpetuation and recurrence of Behcet disease for the activated lymphocytes would not be eliminated through apoptosis mediated by Fas/FasL system.

Objective To develop the information management system in the Department of Radiotherapy,optimize the procedures of radiotherapy, realize the informatization of radiotherapy process management and improve medical efficiency. Methods Multi-digital template was adopted to integrate the information of cancer treatment. The server was equipped with multi-terminal mode to establish the information management system of radiotherapy process. The work authority was assigned according to different positions. The system was connected with radiotherapy plan system (TPS),hospital information system (HIS) and picture archiving and communication system (PACS) to realize the information collection, recording charges, information transmission and plan evaluation and audit in Department of Radiotherapy. Results The information management system optimized the radiotherapy procedures,strengthened connection among different systems, linked the information systems among different departments, standardized the radiotherapy procedures and enhanced the clinical efficiency. Conclusions The application of information management system improves the management level of radiotherapy process, establish a unified standard for cancer treatment and provide complete management plans for the radiotherapy process and quality control. It is a unique and prospective system,which is advantageous in the management of treatment process,systematization of information collection and quality control.