Chui C S, Spirou S, LoSasso T
Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Med Phys. 1996 May;23(5):635-41. doi: 10.1118/1.597699.
It has been shown that intensity-modulated fields have the potential to deliver optimum dose distributions, i.e., high dose uniformity in the target and lower doses in the surrounding critical organs. One way to deliver such fields is by using dynamic multileaf collimation (DMLC). This capability is already available in research mode on some treatment machines. While much effort has been devoted to developing algorithms for DMLC, the mechanical reliability of this new treatment delivery mode has not been fully studied. In this work, we report a series of tests designed to investigate the mechanical aspects of DMLC and their implications on dosimetry. Specifically, these tests were designed to examine (1) the stability of leaf speed, (2) the effect of lateral disequilibrium on dose profiles between adjacent leaves, (3) the significance of acceleration and deceleration of leaf motion, (4) the effect of positional accuracy and rounded-end of the leaves, and (5) create a simple test pattern that may serve as a basis for routine quality assurance checks. Results of these tests are presented. The implications on dosimetry and consideration for the design of leaf motion are discussed.
研究表明，调强射野有潜力实现最佳剂量分布，即在靶区内剂量高度均匀，而在周围关键器官内剂量较低。实现这种射野的一种方法是使用动态多叶准直器（DMLC）。在一些治疗机上，这种功能已在研究模式下可用。虽然已经投入了大量精力来开发DMLC算法，但这种新的治疗投送模式的机械可靠性尚未得到充分研究。在这项工作中，我们报告了一系列旨在研究DMLC机械方面及其对剂量学影响的测试。具体而言，这些测试旨在检查：（1）叶片速度的稳定性；（2）横向不平衡对相邻叶片间剂量分布的影响；（3）叶片运动加速和减速的重要性；（4）位置精度和叶片圆端的影响；（5）创建一个简单的测试模式，可作为常规质量保证检查的基础。给出了这些测试的结果。讨论了对剂量学的影响以及对叶片运动设计的考虑。
