title: Estimated radiation exposure and cancer risk from CT and PET/CT scans in patients with lymphoma.
abstract: BACKGROUND
  The purpose of this study was to estimate total effective dose and cancer risk related to treatment monitoring and surveillance computed tomography (CT) scans in a cohort of patients diagnosed with lymphoma.
  
  
  METHODS
  76 patients with head, neck, chest, abdomen or pelvis CT and whole-body positron emission tomography (PET)/CT were identified from an institutional lymphoma database; this included 54 (71%) patients with non-Hodgkin and 22 (29%) patients with classical Hodgkin lymphoma. Average treatment and surveillance periods were 8 months (range, 3-14 mo) and 23 months (range, 1-40 mo), respectively. Radiation exposure was estimated from the dose-length product (DLP) for CT scans and milli-Curies and DLP for PET/CT scans. Cancer risk was estimated using the Biological Effects of Ionizing Radiation model.
  
  
  RESULTS
  During their treatment period, 45 patients had 161 CT exams and 39 patients had 73 PET/CT exams. Mean effective dose was 39.3 mSv (range, 7.1-100 mSv). During the surveillance period, 60 patients had 378 CT exams and 25 patients had 39 PET/CT exams. Mean effective dose was 53.2 mSv (range, 2.6-154 mSv). Seventeen of 76 (22.4%) patients had total cumulative doses greater than 100 mSv. The mean increase in estimated cancer risk was 0.40%; the greatest estimated risk to any one patient was 1.19%.
  
  
  CONCLUSIONS
  Mean total effective dose and mean estimated cancer risk were low in patients with lymphoma undergoing serial imaging, suggesting that theoretical risks of radiation-induced cancer need not be a major consideration in radiologic follow-up.
authors.affiliation: Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States.
authors.forename: Ravi
authors.initials: R
authors.lastname: Guttikonda
authors.affiliation: Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States; Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States. Electronic address: hertsb@ccf.org.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Herts
authors.affiliation: Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: Dong
authors.affiliation: Imaging Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States; Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Baker
authors.affiliation: Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States.
authors.forename: Kathleen B
authors.initials: KB
authors.lastname: Fenner
authors.affiliation: Taussig Cancer Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, United States.
authors.forename: Brad
authors.initials: B
authors.lastname: Pohlman
mesh_terms: D065638:Absorption, Radiation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001822:Body Burden; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008223:Lymphoma / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000706:statistics & numerical data*; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D009820:Ohio / Q000453:epidemiology; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
keywords: Computed tomography; Lymphoma; Neoplasms; Positron-emission tomography; Radiation; Radiation-induced