伽玛刀辐射场的质量控制测量研究

Gamma Knife Quality Control of Radiation Field

目的通过对伽玛刀辐射场的测量,了解伽玛刀照射野尺寸的偏差和焦平面的半影。方法采用胶片法测量旋转式伽玛刀和静态式伽玛刀共4台伽玛刀的辐射场。结果所测量的4台伽玛刀照射野尺寸与标称值最大偏差1.3 mm;焦平面上照射野半影宽度4号准直器半影最大偏差3.9 mm,8号准直器半影最大偏差5.2 mm,14号准直器半影最大偏差9.0 mm,16号准直器半影最大偏差9.9 mm,18号准直器半影最大偏差10.9 mm,22号准直器半影最大偏差13.0 mm。结论测量的伽玛刀照射野尺寸的偏差和焦平面的半影指标均小于国家标准,可以满足使用。

Objective Through the gamma knife radiation field measurements,to understand the gamma knife radiation field size deviation and the penumbra of the focal plane. Methods Film method was used to measuring rotating gamma knife and static gamma knife,a total of 4 sets of gamma knife radiation field. Results Gamma knife radiation field size and nominal value maximum deviation is 1. 3 mm. Radiation Field on the focal plane width of penumbra collimator penumbra maximum deviation is 3. 9 mm at 4# collimator,8# collimator penumbra maximum deviation is 5. 2 mm,14# collimator penumbra maximum deviation is 9. 0 mm,16# collimator penumbra maximum deviation is 9. 9 mm,18# collimator penumbra maximum deviation is 10. 9 mm are 22# collimator penumbra maximum deviation is 13. 0 mm. Conclusion The measurement of gamma knife radiation field size deviation and the penumbra of the focal plane are less than the national standard which can meet the normal use.