title: Robust PET-guided intensity-modulated radiation therapy.
abstract: OBJECTIVE
  Functional image guided intensity-modulated radiation therapy has the potential to improve cancer treatment quality by basing treatment parameters such as heterogeneous dose distributions information derived from imaging. However, such heterogeneous dose distributions are subject to imaging uncertainty. In this paper, the authors develop a robust optimization model to design plans that are desensitized to imaging uncertainty.
  
  
  METHODS
  Starting from the pretreatment fluorodeoxyglucose-positron emission tomography scans, the authors use the raw voxel standard uptake values (SUVs) as input into a series of intermediate functions to transform the SUV into a desired dose. The calculated desired doses were used as an input into a robust optimization model to generate beamlet intensities. For each voxel, the authors assume that the true SUV cannot be observed but instead resides in an interval centered on the nominal (i.e., observed) SUV. Then the authors evaluated the nominal and robust solutions through a simulation study. The simulation considered the effect of the true SUV being different from the nominal SUV on the quality of the treatment plan. Treatment plans were compared on the metrics of objective function value and tumor control probability (TCP).
  
  
  RESULTS
  Computational results demonstrate the potential for improvements in tumor control probability and deviation from the desired dose distribution compared to a nonrobust model while maintaining acceptable tissue dose.
  
  
  CONCLUSIONS
  Robust optimization can help design treatment plans that are more stable in the presence of image value uncertainties.
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.affiliation: Radiation Oncology, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada Techna Institute for the Advancement of Technology for Health, 124 - 100 College Street, Toronto, Ontario M5G 1P5, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Bissonnette
authors.affiliation: Radiation Oncology, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada Techna Institute for the Advancement of Technology for Health, 124 - 100 College Street, Toronto, Ontario M5G 1P5, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Purdie
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada Techna Institute for the Advancement of Technology for Health, 124 - 100 College Street, Toronto, Ontario M5G 1P5, Canada.
authors.forename: T C Y
authors.initials: TC
authors.lastname: Chan
mesh_terms: D003198:Computer Simulation; D066264:Datasets as Topic; D019788:Fluorodeoxyglucose F18; D056973:Four-Dimensional Computed Tomography / Q000379:methods; D006801:Humans; D009038:Motion; D064847:Multimodal Imaging / Q000379:methods; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000532:radiotherapy; D049268:Positron-Emission Tomography / Q000379:methods*; D011336:Probability; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012119:Respiration; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods; D035501:Uncertainty
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18