Cho P S, Kuterdem H G, Marks R J
Department of Radiation Oncology, University of Washington, Seattle 98195-6043, USA.
Phys Med Biol. 1998 Oct;43(10):3145-8. doi: 10.1088/0031-9155/43/10/032.
Conventional 3D dose calculations for stereotactic radiosurgery involve integration of individual static beams comprising a set of arcs. For iterative optimization of multiple isocentre treatment, which requires repetitive dose calculations at a large number of sample points, the conventional method is too slow. To overcome this problem spherically symmetric dose distributions are assumed. The authors describe a spherical dose model derived from a parametrized convolution of the collimator width and a dose spread kernel. The method is fast and easy to implement requiring just a single empirically derived value. Furthermore, the model is differentiable with respect to the parameters to be optimized. This property is useful when the optimization strategies rely on gradient information.
立体定向放射外科的传统三维剂量计算涉及对由一组弧组成的各个静态射束进行积分。对于多等中心治疗的迭代优化，这需要在大量采样点进行重复剂量计算，传统方法太慢。为克服此问题，假定剂量分布呈球对称。作者描述了一种球形剂量模型，该模型源自准直器宽度与剂量扩散核的参数化卷积。该方法快速且易于实现，仅需一个凭经验得出的值。此外，该模型对于待优化参数是可微的。当优化策略依赖梯度信息时，此属性很有用。
