title: Modeling plan-related clinical complications using machine learning tools in a multiplan IMRT framework.
abstract: OBJECTIVE
  To predict organ-at-risk (OAR) complications as a function of dose-volume (DV) constraint settings without explicit plan computation in a multiplan intensity-modulated radiotherapy (IMRT) framework.
  
  
  METHODS
  Several plans were generated by varying the DV constraints (input features) on the OARs (multiplan framework), and the DV levels achieved by the OARs in the plans (plan properties) were modeled as a function of the imposed DV constraint settings. OAR complications were then predicted for each of the plans by using the imposed DV constraints alone (features) or in combination with modeled DV levels (plan properties) as input to machine learning (ML) algorithms. These ML approaches were used to model two OAR complications after head-and-neck and prostate IMRT: xerostomia, and Grade 2 rectal bleeding. Two-fold cross-validation was used for model verification and mean errors are reported.
  
  
  RESULTS
  Errors for modeling the achieved DV values as a function of constraint settings were 0-6%. In the head-and-neck case, the mean absolute prediction error of the saliva flow rate normalized to the pretreatment saliva flow rate was 0.42% with a 95% confidence interval of (0.41-0.43%). In the prostate case, an average prediction accuracy of 97.04% with a 95% confidence interval of (96.67-97.41%) was achieved for Grade 2 rectal bleeding complications.
  
  
  CONCLUSIONS
  ML can be used for predicting OAR complications during treatment planning allowing for alternative DV constraint settings to be assessed within the planning framework.
authors.affiliation: Industrial and Systems Engineering Department, University of Wisconsin, Madison, WI, USA.
authors.forename: Hao H
authors.initials: HH
authors.lastname: Zhang
authors.forename: Warren D
authors.initials: WD
authors.lastname: D'Souza
authors.forename: Leyuan
authors.initials: L
authors.lastname: Shi
authors.forename: Robert R
authors.initials: RR
authors.lastname: Meyer
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D016001:Confidence Intervals; D003663:Decision Trees; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis / Q000209:etiology; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D010306:Parotid Gland / Q000378:metabolism / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011832:Radiation Injuries / Q000175:diagnosis* / Q000517:prevention & control; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012007:Rectum / Q000528:radiation effects; D012472:Salivation / Q000502:physiology / Q000528:radiation effects; D047368:Tumor Burden; D014987:Xerostomia / Q000175:diagnosis / Q000209:etiology