论文部分内容阅读
目的：分析自制术中放疗限光筒剂量特点。材料与方法：不规则电子线限光筒是用5 mm 厚有机玻璃制作而成。剂量仪使用法码2570型,电离室用NE2571, 0．6 CC。水模中测量射野因子，三维扫描仪在水模中实测射束中心轴百分深度量、OAR、均匀性等，水模为50 cm×50 cm×50 cm。结果：当高于12 MeV电子束时,表面剂量均超过90％，筒径从11～6 cm时表面剂量呈下降趋势,小于6 cm 时有升高迹象，导致剂量的建成区缩短,D max和d 85(15 MeV除外)均向表面移；输出因子在限光筒口径大于5 cm时,趋于稳定，6 MeV时,输出因子随筒径不同而变化较大。结论：我院自制的限光筒优点在于成本低和操作方便，故适合基层医院应用。
OBJECTIVE: To analyze the dose-limiting characteristics of radiotherapy tube in self-made surgery. Materials and Methods: Irregular electronic line light tube is made of 5 mm thick plexiglass. Dosimeter usage code 2570 type, ion chamber with NE2571, 0.6 CC. In water mode, the field factor is measured. The 3D scanner measures the percentage of the central axis of the beam in depth, OAR, uniformity and so on. The water mode is 50 cm × 50 cm × 50 cm. Results: The surface dosages exceeded 90% when the beam diameter was higher than 12 MeV and decreased from 11 ~ 6 cm tube diameter. When the diameter was less than 6 cm, there was a rising trend, which led to the shortening of D max And d 85 (except for 15 MeV) all shift to the surface. The output factor tends to be stable when the diameter of the light-limiting cylinder is larger than 5 cm. At 6 MeV, the output factor varies greatly with the cylinder diameter. Conclusion: The advantages of self-made light-limiting tube in our hospital lie in its low cost and convenient operation, so it is suitable for primary hospital application.