Suh T S, Bova F, Yoon S C, Shinn K S, Bahk Y W
Department of Radiology, Kang-nam St Mary's Hospital, Catholic University Medical College, Seoul, Republic of Korea.
Med Biol Eng Comput. 1993 Jul;31 Suppl:S23-30. doi: 10.1007/BF02446646.
The work presented in the paper addresses a method for obtaining the optimal dose distribution for LINAC-based stereotactic radiosurgery. As many targets have nonspherical or irregular shapes and three-dimensional dose calculations included in dose optimisation, long computation times are required to determine the optimum isocentre separation and collimator sizes to shape the irregular target using the multiple-isocentre approach, by trial-and-error types of method. The simple approach, using a computer-aided design optimisation technique and a fast approximate dose model, has been developed to find the optimum isocentre positions and collimator sizes quickly and automatically. A spherical dose model has been developed to represent the dose for a standard arc system with a single isocentre. The implementation of computer-aided design algorithms with the spherical dose model and their application to several cases are discussed. It is shown that the spherical dose model gives dose distribution similar to that of the exact dose model, which makes this simple dose model more efficient, with computer-aided design optimisation, in finding optimum isocentre positions and collimator sizes used in stereotactic radiosurgery.
本文所展示的工作提出了一种用于获取基于直线加速器的立体定向放射外科最佳剂量分布的方法。由于许多靶区具有非球形或不规则形状，且剂量优化中包含三维剂量计算，因此采用多等中心方法通过试错法来确定使不规则靶区成形的最佳等中心间距和准直器尺寸时，需要很长的计算时间。已开发出一种简单方法，利用计算机辅助设计优化技术和快速近似剂量模型，来快速自动地找到最佳等中心位置和准直器尺寸。已开发出一种球形剂量模型来表示具有单个等中心的标准弧形系统的剂量。讨论了计算机辅助设计算法与球形剂量模型的结合及其在几个案例中的应用。结果表明，球形剂量模型给出的剂量分布与精确剂量模型相似，这使得这种简单剂量模型在计算机辅助设计优化下，在寻找立体定向放射外科中使用的最佳等中心位置和准直器尺寸时更高效。
