title: Projected Effects of Radiation-Induced Cancers on Life Expectancy in Patients Undergoing CT Surveillance for Limited-Stage Hodgkin Lymphoma: A Markov Model.
abstract: OBJECTIVE
  Patients with limited-stage Hodgkin lymphoma (HL) undergo frequent posttreatment surveillance CT examinations, raising concerns about the cumulative magnitude of radiation exposure. The purpose of this study was to project radiation-induced cancer risks relative to competing risks of HL and account for the differential timing of each.
  
  
  METHODS
  We adapted a previously developed Markov model to project lifetime mortality risks and life expectancy losses due to HL versus radiation-induced cancers in HL patients undergoing surveillance CT. In the base case, we modeled 35-year-old men and women undergoing seven CT examinations of the chest, abdomen, and pelvis over 5 years. Radiation-induced cancer risks and deaths for 17 organ systems were modeled using an organ-specific approach, accounting for specific anatomy exposed at CT. Cohorts of 20-, 50-, and 65-year-old men and women were evaluated in secondary analyses. Markov chain Monte Carlo methods were used to estimate the uncertainty of radiation risk projections.
  
  
  RESULTS
  For 35-year-old adults, we projected 3324/100,000 (men) and 3345/100,000 (women) deaths from recurrent lymphoma and 245/100,000 (men, 95% uncertainty interval [UI]: 121-369) and 317/100,000 (women, 95% UI: 202-432) radiation-induced cancer deaths. Discrepancies in life expectancy losses between HL (428 days in men, 482 days in women) and radiation-induced cancers (11.6 days in men, [95% UI: 5.7-17.5], 15.6 days in women [95% UI: 9.8-21.4]) were proportionately greater because of the delayed timing of radiation-induced cancers relative to recurrent HL. Deaths and life expectancy losses from radiation-induced cancers were highest in the youngest cohorts.
  
  
  CONCLUSIONS
  Given the low rate of radiation-induced cancer deaths associated with CT surveillance, modest CT benefits would justify its use in patients with limited-stage HL.
authors.affiliation: 1 Institute for Technology Assessment, Massachusetts General Hospital, 101 Merrimac St, 10th Fl, Boston, MA 02114.
authors.forename: Kathryn P
authors.initials: KP
authors.lastname: Lowry
authors.forename: Ekin A
authors.initials: EA
authors.lastname: Turan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Eisenberg
authors.forename: Chung Y
authors.initials: CY
authors.lastname: Kong
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Barnes
authors.forename: Pari Vijay
authors.initials: PV
authors.lastname: Pandharipande
mesh_terms: D000328:Adult; D000368:Aged; D001900:Boston / Q000453:epidemiology; D015984:Causality; D015897:Comorbidity; D003198:Computer Simulation; D005260:Female; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000401:mortality*; D006801:Humans; D015994:Incidence; D008017:Life Expectancy; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D015233:Models, Statistical; D009367:Neoplasm Staging; D009381:Neoplasms, Radiation-Induced / Q000000981:diagnostic imaging / Q000401:mortality*; D011159:Population Surveillance / Q000379:methods; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000401:mortality*; D055815:Young Adult
keywords: CT; Hodgkin lymphoma; decision analysis; population surveillance; radiation-induced neoplasms