title: Imaging in pediatric patients: time to think again about surveillance.
abstract: BACKGROUND
  Despite concerns regarding ionizing radiation exposures from diagnostic imaging procedures in pediatric patients, many are deemed unavoidable or even mandated by treatment protocols. A prior review at our institution found patients with lymphoma had a higher median cumulative radiation exposure (191 mSv) versus other oncology subgroups (61 mSv).
  
  
  OBJECTIVE
  Estimations of cumulative diagnostic radiation exposures were tabulated for 5 years from the first diagnostic scan for 30 consecutive lymphoma patients diagnosed in 2001. Each individual imaging procedure was reviewed and classified as protocol mandated or discretionary (for disease surveillance, good patient care or radiologist request).
  
  
  RESULTS
  Almost all patients (28/29) received chemotherapy; one had surgery only. Individual cumulative radiation exposures ranged from 10 to 642 mSv. Over 5 years, 690 procedures were performed; 303 (44%) X-rays, 203 (29%) CTs, 157 (23%) radionucleotide, and 27 (4%) interventional procedures. Of these, 238 (34%) were protocol required and 452 (66%) discretionary (224 as part of good patient care for a co-morbid illness and 228 for evaluation of possible disease progression/surveillance). A total of 86/217 (40%) studies (including 43 CTs and 38 radionucleotide scans) were performed when the recurrence risk was low (>2 years off therapy).
  
  
  CONCLUSIONS
  The majority of ionizing radiation procedures in this lymphoma cohort were discretionary. Given the excellent outcome of this group and the long-term risks; rational use of discretionary surveillance procedures is necessary. Guidelines for the appropriate use of surveillance imaging based on probability of risk recurrence must be developed in order to minimize ionizing radiation exposure.
authors.affiliation: Division of Haematology/Oncology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Amy Lee
authors.initials: AL
authors.lastname: Chong
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Grant
authors.forename: Bilal A
authors.initials: BA
authors.lastname: Ahmed
authors.forename: Karen E
authors.initials: KE
authors.lastname: Thomas
authors.forename: Bairbre L
authors.initials: BL
authors.lastname: Connolly
authors.forename: Mark
authors.initials: M
authors.lastname: Greenberg
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008223:Lymphoma / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011839:Radiation, Ionizing; D011859:Radiography / Q000706:statistics & numerical data; D011877:Radionuclide Imaging / Q000706:statistics & numerical data