Interactive Dose Shaping - efficient strategies for CPU-based real-time treatment planning

17th International Conference on the Use of Computers in Radiation Therapy

物理学;计算机科学

Ziegenhein, P.^1 ; Kamerling, C.P.^1 ; Oelfke, U.^1

German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany^1

关键词: Dose-volume histograms;    Efficient strategy;    Intensity-modulated radiation therapy;    Interactive manipulation;    Iterative Optimization;    Objective functions;    Optimal treatment;    Treatment planning;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/489/1/012066/pdf
DOI  :  10.1088/1742-6596/489/1/012066

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Conventional intensity modulated radiation therapy (IMRT) treatment planning is based on the traditional concept of iterative optimization using an objective function specified by dose volume histogram constraints for pre-segmented VOIs. This indirect approach suffers from unavoidable shortcomings: i) The control of local dose features is limited to segmented VOIs. ii) Any objective function is a mathematical measure of the plan quality, i.e., is not able to define the clinically optimal treatment plan. iii) Adapting an existing plan to changed patient anatomy as detected by IGRT procedures is difficult. To overcome these shortcomings, we introduce the method of Interactive Dose Shaping (IDS) as a new paradigm for IMRT treatment planning. IDS allows for a direct and interactive manipulation of local dose features in real-time. The key element driving the IDS process is a two-step Dose Modification and Recovery (DMR) strategy: A local dose modification is initiated by the user which translates into modified fluence patterns. This also affects existing desired dose features elsewhere which is compensated by a heuristic recovery process. The IDS paradigm was implemented together with a CPU-based ultra-fast dose calculation and a 3D GUI for dose manipulation and visualization. A local dose feature can be implemented via the DMR strategy within 1-2 seconds. By imposing a series of local dose features, equal plan qualities could be achieved compared to conventional planning for prostate and head and neck cases within 1-2 minutes. The idea of Interactive Dose Shaping for treatment planning has been introduced and first applications of this concept have been realized.