A two-stage sequential linear programming approach to IMRT dose optimization.
A two-stage sequential linear programming approach to IMRT dose optimization.
复制标题
IMRT 剂量优化的两阶段顺序线性规划方法。
DOI：
10.1088/0031-9155/55/3/022
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发表时间：
2010
影响因子：
3.5
通讯作者：
D'Souza,WarrenD
中科院分区：
文献类型：
--
作者：
Zhang,HaoH;Meyer,RobertR;Wu,Jianzhou;Naqvi,ShahidA;Shi,Leyuan;D'Souza,WarrenD
传统的调强放射治疗计划过程包括两个阶段，第一阶段包括快速但近似的理想化的铅笔束剂量计算和剂量优化，第二阶段包括离散化强度图，随后是强度图分割，以及更准确的对应于物理束流孔径的最终剂量计算。因此，与铅笔束计算和优化相对应的假定剂量分布与考虑到准直器特定效应的更准确地计算出的束段相对应的剂量分布之间可能存在差异。IMRT优化在计算上是昂贵的，因此导致使用不包含解空间的全局视图的启发式方法(例如，模拟退火法和遗传算法)。我们改进了传统的两阶段调强放射治疗优化过程，通过基于蒙特卡罗的精确核叠加剂量计算和基于精确数学规划的使用线性规划(SLP)的顺序优化方法相结合来增强第二阶段。我们的方法在三个具有挑战性的临床测试案例上进行了测试，这些测试案例对应于两个供应商的多叶准直器限制。我们将我们的方法与传统的调强放疗计划方法、直接孔径方法和节段权重优化方法进行了比较。我们在所有三种情况下的结果都表明，SLP方法优于其他方法，实现了更好的关键结构节省。我们的方法的收敛也被证明。最后，我们的方法也已与商业治疗计划系统集成，并可能用于临床。
The conventional IMRT planning process involves two stages in which the first stage consists of fast but approximate idealized pencil beam dose calculations and dose optimization and the second stage consists of discretization of the intensity maps followed by intensity map segmentation and a more accurate final dose calculation corresponding to physical beam apertures. Consequently, there can be differences between the presumed dose distribution corresponding to pencil beam calculations and optimization and a more accurately computed dose distribution corresponding to beam segments that takes into account collimator-specific effects. IMRT optimization is computationally expensive and has therefore led to the use of heuristic (eg, simulated annealing and genetic algorithms) approaches that do not encompass a global view of the solution space. We modify the traditional two-stage IMRT optimization process by augmenting the second stage via an accurate Monte Carlo-based kernel-superposition dose calculations corresponding to beam apertures combined with an exact mathematical programming-based sequential optimization approach that uses linear programming (SLP). Our approach was tested on three challenging clinical test cases with multileaf collimator constraints corresponding to two vendors. We compared our approach to the conventional IMRT planning approach, a direct-aperture approach and a segment weight optimization approach. Our results in all three cases indicate that the SLP approach outperformed the other approaches, achieving superior critical structure sparing. Convergence of our approach is also demonstrated. Finally, our approach has also been integrated with a commercial treatment planning system and may be utilized clinically.