On-line re-optimization of prostate IMRT plans for adaptive radiation therapy
On-line re-optimization of prostate IMRT plans for adaptive radiation therapy
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DOI：
10.1088/0031-9155/53/3/011
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发表时间：
2008-02-07
影响因子：
3.5
通讯作者：
Yin, Fang-Fang
中科院分区：
文献类型：
--
作者：
Wu, Q. Jackie;Thongphiew, Danthai;Yin, Fang-Fang
对于中度和高度风险前列腺癌，前列腺和精囊都包括在临床目标体积中。这两个器官的内部运动模式各不相同，对适应性治疗提出了挑战。自适应技术，如等中心重新定位和软组织对齐是有效的，当肿瘤体积只表现出平移移位，而直接重新优化的调强放射治疗（IMRT）计划可能更可取的极端变形或差异定位变化的器官发生时。目前，还没有报道使用小射束（或注量图）直接重新优化IMRT计划。在这项研究中，我们报告了一种新的在线再优化技术，可以完成计划调整在线。可变形图像配准用于提供关于每个体素的沿三维沿着的位置变化信息。原始计划剂量分布被用作适应的“目标”剂量分布，以确保计划质量。通过线性规划重新优化通量图，可在2分钟内获得计划解决方案。通过一个大变形的临床病例证明了该技术的可行性。这种在线ART过程对于低分割前列腺IMRT治疗可能是非常有价值的。
For intermediate and high risk prostate cancer, both the prostate gland and seminal vesicles are included in the clinical target volume. Internal motion patterns of these two organs vary, presenting a challenge for adaptive treatment. Adaptive techniques such as isocenter repositioning and soft tissue alignment are effective when tumor volumes only exhibit translational shift, while direct re-optimization of the intensity-modulated radiation therapy (IMRT) plan maybe more desirable when extreme deformation or differential positioning changes of the organs occur. Currently, direct re-optimization of the IMRT plan using beamlet (or fluence map) has not been reported. In this study, we report a novel on-line re-optimization technique that can accomplish plan adjustment on-line. Deformable image registration is used to provide position variation information on each voxel along the three dimensions. The original planned dose distribution is used as the 'goal' dose distribution for adaptation and to ensure planning quality. Fluence maps are re-optimized via linear programming, and a plan solution can be achieved within 2min. The feasibility of this technique is demonstrated with a clinical case with large deformation. Such on-line ART process can be highly valuable with hypo-fractionated prostate IMRT treatment.