Siddon R L, Barth N H
Int J Radiat Oncol Biol Phys. 1987 Aug;13(8):1241-6. doi: 10.1016/0360-3016(87)90201-x.
We report on a useful clinical method for precisely locating intracranial targets. Utilizing the BRW system, the technique is currently used in stereotaxic irradiation of arteriovenous malformations. An intracranial localizer box, with four radio-opaque markers on each face, surrounds the patient's head and is attached to the BRW Head Ring. Two localization films are required. One film includes the target and the eight anterior and posterior markers, whereas the other film includes the target and the eight right and left markers. There are no constraints that the films be orthogonal or parallel to the box faces, only that the target and radio-opaque markers appear on the films. In addition, knowledge of the source-image and source-target distances are not required. Analysis of the projected target and radio-opaque markers gives both the target location and magnification. Simulation with the BRW Phantom Base demonstrates that point targets can be located with respect to the BRW system to within 0.3 mm and magnification determined to within 0.5%.
我们报告了一种精确确定颅内靶点的实用临床方法。利用BRW系统，该技术目前用于动静脉畸形的立体定向放射治疗。一个颅内定位盒，每面有四个不透射线的标记物，环绕患者头部并连接到BRW头环上。需要两张定位片。一张片子包括靶点以及八个前后标记物，而另一张片子包括靶点以及八个左右标记物。片子无需与定位盒面正交或平行，只要靶点和不透射线的标记物出现在片子上即可。此外，不需要知道源图像和源靶点距离。对投射的靶点和不透射线的标记物进行分析可得出靶点位置和放大倍数。使用BRW体模底座进行模拟表明，相对于BRW系统，点靶点的定位精度可达0.3毫米以内，放大倍数的确定精度可达0.5%以内。
