Robustness Quantification and Worst-Case Robust Optimization in Intensity-Modulated Proton Therapy


Intensity-Modulated Proton Therapy (IMPT) is highly sensitive to uncertainties in beam range, patient setup and organ motion. Therefore, it is essential to evaluate the robustness of the IMPT plans against these uncertainties and design robustly optimized plans to improve the plan quality. The root-mean-square-dose volume histograms (RVH) measure the sensitivity of the dose to uncertainties and the areas under the RVH curve (AUCs) can be used to evaluate plan robustness. Results of our research have shown the following. In the worst case and nominal scenarios, robustly optimized plans have better target coverage, improved dose homogeneity, and lower or equivalent dose to organs at risk (OARs). Additionally, robust optimization provides significantly more robust dose distributions to targets and organs than conventional optimization in IMPT. Reduction of PTV and planning directly based on CTV provides better or equivalent OAR sparing. Also 4D robust optimization provides more respiratory-motion-insensitive plans compared to 3D robust optimization.


Planning Target Volume Dose Distribution Clinical Target Volume Robust Optimization Proton Therapy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to thank Dr. Martin Bues for many instructive discussions. This research was supported by the National Cancer Institute through grants P01CA021239, K25CA168984, and the Fraternal Order of Eagles Cancer Research Fund, Career Development Award Program, and The Lawrence W. and Marilyn W. Matteson Fund for Cancer Research.


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Copyright information

© Springer India 2016

Authors and Affiliations

  1. 1.Department of Radiation OncologyMayo Clinic in ArizonaPhoenixUSA

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