Perec A, Kubo H
Department of Radiation Oncology, University of Rochester Cancer Center, New York 14642.
Med Phys. 1990 Jul-Aug;17(4):715-9. doi: 10.1118/1.596472.
Radiation leakage through electron applicators by 6-, 9-, 12-, 16-, and 20-MeV electron beams from Varian Clinac-1800 has been measured with films. High levels of leakage were found under the corners of applicators and the touch-plate mounting port holes. The radiation leakage, relative to the central-axis dose at dmax, was found to be up to 13% on the patient plane [100-cm source-to-film distance (SFD)] and up to 35% beneath the corners of applicators (96-cm SFD). Up to 18% radiation leakage was measured beneath the touch plate near the mounting port holes (96-cm SFD). The extent of radiation leakage in all electron beams was investigated and some simple shielding solutions to reduce the leakage are suggested.
利用胶片测量了Varian Clinac - 1800的6兆电子伏、9兆电子伏、12兆电子伏、16兆电子伏和20兆电子伏电子束通过电子限光筒的辐射泄漏情况。在限光筒的拐角下方和触摸板安装端口孔处发现了高水平的泄漏。相对于dmax处的中心轴剂量，在患者平面（源到胶片距离100厘米）上的辐射泄漏高达13%，在限光筒拐角下方（源到胶片距离96厘米）高达35%。在靠近安装端口孔的触摸板下方测量到高达18%的辐射泄漏。研究了所有电子束的辐射泄漏程度，并提出了一些减少泄漏的简单屏蔽解决方案。
