Mitch M G, Zimmerman B E, Lamperti P J, Seltzer S M, Coursey B M
Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Med Phys. 2000 Oct;27(10):2293-6. doi: 10.1118/1.1290715.
The response of well-ionization chambers to the emissions of 103Pd and 125I radioactive seed sources used in prostate cancer brachytherapy has been measured. Calibration factors relating chamber response (current or dial setting) to measured air-kerma strength have been determined for seeds from nine manufacturers, each with different designs. Variations in well-ionization chamber response relative to measured air-kerma strength have been observed because of differences in the emitted energy spectrum due to both the radionuclide support material (125I seeds) and the mass ratio of 103Pd to 102Pd (103Pd seeds). Obtaining accurate results from quality assurance measurements using well-ionization chambers at a therapy clinic requires knowledge of such differences in chamber response as a function of seed design.
已测量了良好电离室对前列腺癌近距离治疗中使用的¹⁰³Pd和¹²⁵I放射性籽源发射的响应。已确定了九个制造商生产的不同设计种子的电离室响应（电流或刻度盘设置）与测量的空气比释动能强度之间的校准因子。由于放射性核素载体材料（¹²⁵I种子）和¹⁰³Pd与¹⁰²Pd的质量比（¹⁰³Pd种子）导致发射能谱存在差异，因此观察到了良好电离室响应相对于测量的空气比释动能强度的变化。在治疗诊所使用良好电离室进行质量保证测量时，要获得准确结果需要了解电离室响应随种子设计的这种差异。
