Wilson D L, Sharma S C, Jose B
Int J Radiat Oncol Biol Phys. 1986 Jun;12(6):1007-11. doi: 10.1016/0360-3016(86)90399-8.
The Therac 20 is an AECL medical linear accelerator that produces electron and photon beams. Electron fields are produced by a scanned beam; collimation is provided by two sets of primary collimators and further collimated by external electron trimmers located 11 cm above the plane of isocenter (100 cm). These collimators are not suitable for intracavitary treatment. To overcome this limitation, we have designed an intracavitary cone system that attaches to the electron trimmers. Since the trimmers do not have to be removed while this system is in use, there is no need to bypass the associated interlock system. The apparatus consists of a platform which slides onto the lower set of trimmers, onto which a lead insert is attached. Dosimetry measurements for 9, 13, and 17 MeV electron beams are reported for three different treatment cones.
Therac 20是加拿大原子能公司生产的一种医用直线加速器，可产生电子束和光子束。电子束由扫描束产生；准直由两组初级准直器提供，并由位于等中心平面（100 cm）上方11 cm处的外部电子微调器进一步准直。这些准直器不适用于腔内治疗。为克服这一限制，我们设计了一种连接到电子微调器的腔内锥形系统。由于在使用该系统时无需移除微调器，因此无需绕过相关的联锁系统。该装置由一个可滑到下部微调器组上的平台组成，平台上连接有一个铅插入件。报告了三种不同治疗锥体的9、13和17 MeV电子束的剂量测定结果。
