Markus B, Kasten G
Abteilung Klinische Strahlenbiologie und Klinische Strahlenphysik, Universität Göttingen.
Strahlenther Onkol. 1988 Apr;164(4):228-34.
A device is described which allows to perform dosimetry with a usual flat chamber made of plexiglas (PTW soft ray chamber) in the water phantom. The depth dose curves measured for anode potentials of 10 to 100 kV were compared to the curves measured a) in a plexiglas phantom, b) in a M3 phantom using a soft ray chamber made of M3, c) in a mixed phantom consisting of a plexiglas bottom, a soft ray chamber made of plexiglas flush with its surface, and plates or foils made of M3, polystyrene, and frapan. The results show that there is no difference between the depth dose curves measured in water and those measured in the homogeneous M3 phantom if the curve is plotted over the mass related to the surface (g/cm2). There is also no difference to the dose curve measured in the mixed phantom according to c) if M3 plates determining the depth of measurement are layed on it. With the other substances, considerable deviations are found. An example is presented in order to warn against the uncontrolled use of "plastic foils" as phantom material for soft ray depth dose curves.
本文描述了一种装置，它能够使用由有机玻璃制成的普通扁平电离室（PTW软射线电离室）在水模体中进行剂量测定。将10至100 kV阳极电位下测得的深度剂量曲线与以下几种情况下测得的曲线进行比较：a）在有机玻璃体模中；b）在使用由M3制成的软射线电离室的M3体模中；c）在由有机玻璃底部、与表面齐平的由有机玻璃制成的软射线电离室以及由M3、聚苯乙烯和弗拉潘制成的板或箔组成的混合体模中。结果表明，如果将曲线绘制在与表面相关的质量（g/cm²）上，那么在水中测得的深度剂量曲线与在均匀的M3体模中测得的曲线之间没有差异。如果在混合体模上放置用于确定测量深度的M3板，那么与根据c）在混合体模中测得的剂量曲线也没有差异。对于其他物质，会发现有相当大的偏差。给出了一个例子，以警示不要无控制地使用“塑料箔”作为软射线深度剂量曲线的体模材料。
