title: Comparative Risk Predictions of Second Cancers After Carbon-Ion Therapy Versus Proton Therapy.
abstract: OBJECTIVE
  This work proposes a theoretical framework that enables comparative risk predictions for second cancer incidence after particle beam therapy for different ion species for individual patients, accounting for differences in relative biological effectiveness (RBE) for the competing processes of tumor initiation and cell inactivation. Our working hypothesis was that use of carbon-ion therapy instead of proton therapy would show a difference in the predicted risk of second cancer incidence in the breast for a sample of Hodgkin lymphoma (HL) patients.
  
  
  METHODS
  We generated biologic treatment plans and calculated relative predicted risks of second cancer in the breast by using two proposed methods: a full model derived from the linear quadratic model and a simpler linear-no-threshold model.
  
  
  RESULTS
  For our reference calculation, we found the predicted risk of breast cancer incidence for carbon-ion plans-to-proton plan ratio, <Rc/Rp>, to be 0.75 ± 0.07 but not significantly smaller than 1 (P=.180).
  
  
  CONCLUSIONS
  Our findings suggest that second cancer risks are, on average, comparable between proton therapy and carbon-ion therapy.
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; University of Texas Graduate School of Biomedical Sciences, Houston, Texas; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland. Electronic address: jeley@som.umaryland.edu.
authors.forename: John G
authors.initials: JG
authors.lastname: Eley
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Friedrich
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; University of Texas Graduate School of Biomedical Sciences, Houston, Texas.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Homann
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas; University of Texas Graduate School of Biomedical Sciences, Houston, Texas.
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Howell
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Scholz
authors.affiliation: GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Durante
authors.affiliation: Department of Physics and Astronomy, Louisiana State University and Agricultural and Mechanical College, Baton Rouge, Louisiana; Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana.
authors.forename: Wayne D
authors.initials: WD
authors.lastname: Newhauser
mesh_terms: D001940:Breast / Q000528:radiation effects; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D002244:Carbon / Q000009:adverse effects / Q000627:therapeutic use; D004947:Esophagus / Q000528:radiation effects; D005260:Female; D006321:Heart / Q000528:radiation effects; D063193:Heavy Ion Radiotherapy / Q000009:adverse effects*; D006689:Hodgkin Disease / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008168:Lung / Q000528:radiation effects; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000209:etiology*; D058958:Organs at Risk / Q000000981:diagnostic imaging; D061766:Proton Therapy / Q000009:adverse effects*; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012062:Relative Biological Effectiveness; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000528:radiation effects; D035501:Uncertainty
chemical_list: D002244:Carbon