The Study On The Raduced Radiology Dose Of Proton Accelerator Treatment System

Background:With increasing levels of health care and proton therapy system of continuous improvement and cost reduction, there will be more proton therapy system put into clinical use in the future.Therefore, for the protection of the health of radiation workers to safeguard the smooth progress of proton therapy, to carry out the treatment system induced radioactivity of proton accelerator research is necessary. This research lay a good foundation for occupational health standards of proton accelerator treatment systems and induced radioactivity.Induced radioactivity is usually the result of neutron activation, when the beam is stopped, there are "left" phenomenon of radiation. High energy particle accelerators (greater than lOMeV) produce induced radioactivity are possible through (y-n),(p-n) nuclear reactions such as neutron leakage or contamination. Induced radioactivity decreases rapidly, usually2to10minutes can be reduced by half or more, such as personnel immediately after stopping the beam into the radiation therapy room, may be subject to irradiation induced radioactivity. International awareness of medical electron accelerators produce neutrons and induced radioactivity leakage were more discussion, but proton accelerator therapy system induced radioactivity studies have not been conducted.In1991, the U.S. Loma Linda University Medical Center dedicated proton first enable the medical device, the current international biological effects on proton therapy and cancer treatment in the ascendant. As high-energy protons (230MeV above) into the body tissues, in a certain depth can produce sharp Bragg peaks (Bragg Peak), the energy is concentrated in the tumor site, so proton therapy cancer technology has become the world’s cancer treatment priority High-tech. Domestic proton accelerator radiation therapy started late, until2005, was introduced by the IBA Zibo Wan Jie Group company230MeV proton accelerator treatment system. Since wanjie proton accelerator began formal operations, I have been concerned about the project’s research, reading MPH during research for a more systematic and analyzed.The results show that proton accelerator treatment system induced radioactivity levels are higher. When the proton energy221.79MeV run down five minutes after5minutes, the placement officer at the induced radioactivity of up41μGy/h. General Medical electron accelerators15MV X-ray irradiation6.27minutes (dose of about40Gy), the corresponding position only1.12～1.38μGy/h. However, this situation is just the device only when debugging or maintenance of a long beam, and no patient or phantom block, the energy loss in the treatment of the bed completely, which leads to this state of affairs.Through this study shows that due to the accumulation of induced radioactivity, which produces a radiation effect for radiation workers will increase year by year, for the control of the occupational hazards, should be long-term concern of the project to strengthen the radiation dose monitoring staff to strengthen their radiological protection awareness, strict system of its work, in order to reduce the induced radioactivity of staff health hazards.