Optimization Of Medical Electron Linear Accelerator Old Room Reconstruction Radiation Protection Research

New cases of malignant tumors showed a rapid growth trend, cancer incidence and mortality remain high for long. One of the three main methods of radiation therapy as a cancer treatment, clinical treatment is the most widely used and effective therapy. Medical linear accelerator radiotherapy is the most important medical equipment, there are many new medical linear accelerator using a TBI(total body irradiation), IMRT(intensity modulated radiotherapy) and SRT(stereotactic radiotherapy) and other new technologies. Compared with conventional radiotherapy methods, these techniques applied to the patient a higher dose absorbed, resulting in significant increase in workload and usage factors, but also on the associated medical linear accelerator room shielded put forward higher requirements.Hospital updating medical linear accelerator room renovation, the need to focus on assessing and optimizing Accelerator shielding design to optimize the economic costs and the shielding effect.Taking a hospital medical electron linear accelerator old room renovation process optimization of radiation protection research. Combined with the actual situation in a hospital, explore the shielding design goals of medical electron linear accelerator room converted old involved, and their respective venues partition masker optimization analysis to calculate the shielding calculation times, protective doors and fans tract. With related parameters to be introduced medical linear accelerator at the corresponding work load and use factors, discussed the impact of the special circumstances of different shielding materials and shielding thickness and some, such as the sky scattering radiation shielding thickness. And calculated 6MV old energy medical linear accelerator upgrade to a maximum of two-photon energy 18 MV Medical Electron Linear Accelerator for the entire thickness of the shield room influence. Preliminary analysis of results:(1) are the main concrete shielding material optimization, the main shield will fully absorb all of the light neutron capture gamma rays and neutrons.(2) When the engine room space is limited structure, radiation shielding optimization alternative is part of the wall of the main shield of steel or lead. When rebuilding the engine room is typically lead more economical, consistent with ALARA principles.(3) the maximum energy 18 MV accelerators required master shield ordinary concrete thickness of about 150cm; treatment head toward the second shielding required thickness of 94.7cm; non-head toward the second shield thickness of 87cm; shield about secret door lead and 54 mm of the BPE 7mm(boron polyethylene).