Pike B, Podgorsak E B, Peters T M, Pla C
Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada.
Med Phys. 1987 Sep-Oct;14(5):780-9. doi: 10.1118/1.596003.
A treatment planning technique for calculation of dose distributions in dynamic stereotactic "radiosurgery" with a 10-MV isocentrically mounted linear accelerator is presented. The treatment planning for dynamic radiosurgery is a three-dimensional problem, since during treatment both the gantry and the couch rotate simultaneously, the gantry from 30 degrees to 330 degrees and the couch from 75 degrees to - 75 degrees. The patient surface and anatomical information is obtained from a family of computed tomography or magnetic resonance scans, and a stereotactic frame is used for target localization, treatment setup, and patient immobilization during the treatment. The dose calculational algorithm follows the gantry and couch rotation in an incremental fashion, and relies on measured stationary beam central axis percentage depth doses and dose profiles to calculate the normalized tissue-maximum-ratio distributions over a matrix of points defined on one of three orthogonal planes (transverse, sagittal, or coronal). The dose calculation algorithm is discussed in detail and calculated dose distributions for single plane and dynamic radiosurgery compared with measured data.
本文介绍了一种利用10兆伏等中心安装的直线加速器在动态立体定向“放射外科”中计算剂量分布的治疗计划技术。动态放射外科的治疗计划是一个三维问题，因为在治疗过程中，机架和治疗床会同时旋转，机架从30度旋转到330度，治疗床从75度旋转到 -75度。患者表面和解剖信息通过一系列计算机断层扫描或磁共振扫描获得，并且在治疗期间使用立体定向框架进行靶区定位、治疗设置和患者固定。剂量计算算法以增量方式跟踪机架和治疗床的旋转，并依靠测量的静态射束中心轴百分深度剂量和剂量分布来计算在三个正交平面（横向、矢状或冠状）之一上定义的点矩阵上的归一化组织最大剂量比分布。详细讨论了剂量计算算法，并将单平面和动态放射外科的计算剂量分布与测量数据进行了比较。
