van de Geijn J, Harrington F S
Int J Radiat Oncol Biol Phys. 1984 Dec;10(12):2375-9. doi: 10.1016/0360-3016(84)90248-7.
A simple mechanical back-projection system for X ray films is described which is easy to construct and implement. It enables mechanical simulation of the X ray geometry used when taking pairs of isocentric radiographs for reconstruction purposes. Such pairs may be conventional "AP and Lateral" sets but often it is preferable to take them in oblique directions on the order of 90 degrees apart. The device and the reconstruction method have proved to be very useful in determining target volumes for radiation treatment planning, especially if surgical clips and/or distinct anatomical structures are present. As an instructional tool it has advantages over an also locally developed computer-assisted method of reconstruction. The present system has proved to be highly useful especially in delineating the target volume for treatment planning of soft tissue sarcomas of the extremities and peripheral parts of the body, where detailed and accurate tailoring of shielding blocks is often of vital importance.
描述了一种用于X线片的简单机械反投影系统，该系统易于构建和实施。它能够对为重建目的拍摄等中心X线片对时所使用的X线几何形状进行机械模拟。这样的片子对可以是传统的“前后位和侧位”组合，但通常更倾向于在大约90度间隔的斜向方向拍摄。该装置和重建方法已被证明在确定放射治疗计划的靶体积方面非常有用，特别是当存在手术夹和/或明显的解剖结构时。作为一种教学工具，它比同样在当地开发的计算机辅助重建方法具有优势。目前的系统已被证明非常有用，特别是在描绘肢体和身体外周软组织肉瘤治疗计划的靶体积时，在这种情况下，精确裁剪屏蔽块往往至关重要。
