Shepard D M, Olivera G, Angelos L, Sauer O, Reckwerdt P, Mackie T R
Department of Medical Physics, University of Wisconsin-Madison, 53706-1532, USA.
Med Phys. 1999 Jul;26(7):1212-21. doi: 10.1118/1.598615.
Convolution/superposition software has been used to produce a library of photon pencil beam dose matrices. This library of pencil beams is designed to serve as a tool for both education and investigation in the field of radiotherapy optimization. The elegance of this pencil beam model stems from its cylindrical symmetry. Because of the symmetry, the dose distribution for a pencil beam from any arbitrary angle can be determined through a simple rotation of a pre-computed dose matrix. Rapid dose calculations can thus be performed while maintaining the accuracy of a convolution/superposition based dose computation. The pencil beam data sets have been made publicly available. It is hoped that the data sets will facilitate a comparison of a variety of optimization and delivery approaches. This paper will present a number of studies designed to demonstrate the usefulness of the pencil beam data sets. These studies include an examination of the extent to which a treatment plan can be improved through either an increase in the number of beam angles and/or a decrease in the collimator size. A few insights into the significance of heterogeneity corrections for treatment planning for intensity modulated radiotherapy will also be presented.
卷积/叠加软件已被用于生成光子笔形束剂量矩阵库。这个笔形束库旨在作为放射治疗优化领域教育和研究的工具。这个笔形束模型的精妙之处源于其圆柱对称性。由于这种对称性，来自任意角度的笔形束的剂量分布可以通过预先计算的剂量矩阵的简单旋转来确定。因此，可以在保持基于卷积/叠加的剂量计算准确性的同时进行快速剂量计算。笔形束数据集已公开提供。希望这些数据集将有助于比较各种优化和输送方法。本文将介绍一些旨在证明笔形束数据集有用性的研究。这些研究包括考察通过增加射野角度数量和/或减小准直器尺寸可以在多大程度上改善治疗计划。还将对调强放射治疗治疗计划中不均匀性校正的重要性提供一些见解。
