Prasad S C, Chung C T
SUNY Health Science Center, Department of Radiology 13210, USA.
Med Dosim. 1995 Spring;20(1):15-8. doi: 10.1016/0958-3947(94)00042-h.
Dose to a surface parallel to an incident photon beam has been investigated in the presence of air gaps and air cavities. Measurements have been made in an acrylic phantom with a parallel plate chamber. Photon beams of Co 60, 4-MV, 6-MV, and 15-MV X-rays have been investigated. The results of our measurements show that in the case of air gaps, the dose reduction to a tangential surface is considerable. On the other hand, the dose reduction is 2% or less in the case of air cavity for volumes encountered in clinical situations.
在存在气隙和空气腔的情况下，对与入射光子束平行的表面剂量进行了研究。使用平行板电离室在丙烯酸模体中进行了测量。对钴60、4兆伏、6兆伏和15兆伏X射线的光子束进行了研究。我们的测量结果表明，在气隙情况下，切向表面的剂量降低相当可观。另一方面，对于临床中遇到的体积，空气腔情况下的剂量降低为2%或更低。
