Cormack R A
Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02215, USA.
Med Phys. 1998 Jun;25(6):879-84. doi: 10.1118/1.598263.
Determining the beam configuration necessary to deliver a desired dose distribution with rotation therapy is equivalent to solving an integral equation. The equation has been solved analytically for a handful of dose distributions having specific radial variation and either rotational or reflective angular symmetry. In this work a numerical method for calculating beam profiles appropriate for producing distributions having arbitrary radial variation and angular symmetry of order l > or = 2 is presented. The accuracy of the technique is demonstrated by comparison with one of the few dose distributions for which an analytic solution exists, and the ability to produce both more general and conformal distributions is also shown. The problems of negative intensity and scatter are discussed.
确定采用旋转治疗来实现所需剂量分布所需的射束配置等同于求解一个积分方程。对于少数具有特定径向变化以及旋转或反射角对称性的剂量分布，该方程已通过解析法求解。在这项工作中，提出了一种数值方法，用于计算适合产生具有任意径向变化和l≥2阶角对称性分布的射束轮廓。通过与少数存在解析解的剂量分布之一进行比较，证明了该技术的准确性，并且还展示了产生更通用和适形分布的能力。讨论了负强度和散射问题。
