Bonnett D E, Williams J R, Parnell C J
Br J Radiol. 1980 Jan;53(625):12-20. doi: 10.1259/0007-1285-53-625-12.
A second fast neutron beam for radiotherapy has been brought into operation at the Western General Hospital, Edinburgh. This beam is isocentrically mounted and can be rotated through +/- 120 deg from the vertical. Neutrons are produced by bombarding a thick beryllium target with 15 MeV deuterons. The provision of an isocentric facility enables some of the problems associated with poor beam penetration to be alleviated. The physical features of the isocentric facility are described with particular reference to the shielding and the methods employed to overcome problems of neutron activation. Both the prompt radiation leakage and the induced activity have been measured. It has been found that for the first eight months of operation the whole body dose-equivalent to radiographers was approximately 6 microSv (0.6 mrem) per patient treated. Dosimetry associated with the facility is discussed and an example of a seven field treatment plan for a bladder is presented.
爱丁堡西部总医院已启用第二台用于放射治疗的快中子束。该束线采用等中心安装，可从垂直方向旋转±120度。通过用15兆电子伏特的氘核轰击厚铍靶来产生中子。等中心设备的提供使得与束流穿透性差相关的一些问题得到缓解。描述了等中心设备的物理特性，特别提及了屏蔽以及用于克服中子活化问题的方法。已测量了瞬发辐射泄漏和感生放射性。结果发现，在运行的前八个月中，每位接受治疗的患者给予放射技师的全身剂量当量约为6微希沃特（0.6毫雷姆）。讨论了与该设备相关的剂量测定，并给出了一个膀胱七野治疗计划的示例。
