title: Selective robust optimization: A new intensity-modulated proton therapy optimization strategy.
abstract: OBJECTIVE
  To develop a new robust optimization strategy for intensity-modulated proton therapy as an important step in translating robust proton treatment planning from research to clinical applications.
  
  
  METHODS
  In selective robust optimization, a worst-case-based robust optimization algorithm is extended, and terms of the objective function are selectively computed from either the worst-case dose or the nominal dose. Two lung cancer cases and one head and neck cancer case were used to demonstrate the practical significance of the proposed robust planning strategy. The lung cancer cases had minimal tumor motion less than 5 mm, and, for the demonstration of the methodology, are assumed to be static.
  
  
  RESULTS
  Selective robust optimization achieved robust clinical target volume (CTV) coverage and at the same time increased nominal planning target volume coverage to 95.8%, compared to the 84.6% coverage achieved with CTV-based robust optimization in one of the lung cases. In the other lung case, the maximum dose in selective robust optimization was lowered from a dose of 131.3% in the CTV-based robust optimization to 113.6%. Selective robust optimization provided robust CTV coverage in the head and neck case, and at the same time improved controls over isodose distribution so that clinical requirements may be readily met.
  
  
  CONCLUSIONS
  Selective robust optimization may provide the flexibility and capability necessary for meeting various clinical requirements in addition to achieving the required plan robustness in practical proton treatment planning settings.
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and Department of Applied Research, Varian Medical Systems, Palo Alto, California 94304.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Applied Research, Varian Medical Systems, Palo Alto, California 94304.
authors.forename: Perttu
authors.initials: P
authors.lastname: Niemela
authors.affiliation: Department of Industrial Engineering, University of Houston, Houston, Texas 77004.
authors.forename: Li
authors.initials: L
authors.lastname: Liao
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and Department of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300040, China.
authors.forename: Shengpeng
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: Falk
authors.initials: F
authors.lastname: Poenisch
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: X Ronald
authors.initials: XR
authors.lastname: Zhu
authors.affiliation: Department of Applied Research, Varian Medical Systems, Palo Alto, California 94304.
authors.forename: Sami
authors.initials: S
authors.lastname: Siljamaki
authors.affiliation: Department of Applied Research, Varian Medical Systems, Palo Alto, California 94304.
authors.forename: Reynald
authors.initials: R
authors.lastname: Vanderstraeten
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: Narayan
authors.initials: N
authors.lastname: Sahoo
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: Michael
authors.initials: M
authors.lastname: Gillin
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000465:Algorithms; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D061766:Proton Therapy / Q000379:methods*; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014057:Tomography, X-Ray Computed