论文部分内容阅读
目的研究不同照射条件下医用加速器机房周围环境X射线辐射水平。方法参考《建设项目职业病危害放射防护评价规范第2部分:放射治疗装置》(GBZ/T 220.2-2009)以Synergy型10 MV加速器为研究对象,使用451B电离室型X、γ剂量率仪,分为等中心处放置模体组和无模体组,分别在四种不同的机架角度(0°、90°、180°、270°)测量机房四周屏蔽墙及防护门处周围剂量当量率,并对检测结果进行分析。结果等中心放置模体组中,机架90°时,西墙外X射线周围剂量当量率大于其他角度;270°时,东墙外X射线周围剂量当量率最大;机架270°时防护门处周围剂量当量率高于其它角度的检测结果,差异有统计学意义;同不放置模体组比较,放置模体组防护门处周围剂量当量率明显增高,且270°时剂量率是不放置模体的1.5倍,但四周屏蔽墙周围剂量当量率却无显著差别。结论医用加速器机房四周屏蔽墙及防护门口X射线辐射水平随机架角度的变化而不同;检测门口辐射水平时,应设置模体。
Objective To study the X-ray radiation of the surroundings of medical accelerator room under different irradiation conditions. Methods Refer to “Part 2 of Radiation Protection Evaluation Criteria for Occupational Hazards in Construction Project” (GBZ / T 220.2-2009). The Synergy 10 MV accelerator was used as the research object. The 451B ionization chamber type X and γ dose rate meters For the isocenter center, the phantom group and the phantom group were placed. The dose equivalence rate around the shield wall and the protective door around the engine room was measured at four different rack angles (0 °, 90 °, 180 °, 270 °) And the test results were analyzed. Results In the center of the phantom, when the frame is 90 °, the dose equivalent ratio around the X-ray outside the west wall is larger than other angles; at 270 °, the dose equivalent ratio around the X-ray outside the east wall is the largest; The dose equivalence ratio around the place is higher than other angles of the test results, the difference was statistically significant; compared with the phantom group, placed phantom group around the protective door dose equivalent rate was significantly increased, and 270 ° when the dose rate is not placed 1.5 times the body, but around the shield wall dose equivalent rate was no significant difference. Conclusion The X-ray radiation levels of the shielding walls and protective doorways around the medical accelerator room vary with the changes of the angle of the gantry. When the radiation level of the doorway is detected, the phantom should be set.