title: A Comparative Evaluation of Normal Tissue Doses for Patients Receiving Radiation Therapy for Hodgkin Lymphoma on the Childhood Cancer Survivor Study and Recent Children's Oncology Group Trials.
abstract: Survivors of pediatric Hodgkin lymphoma (HL) are recognized to have an increased risk of delayed adverse health outcomes related to radiation therapy (RT). However, the necessary latency required to observe these late effects means that the estimated risks apply to outdated treatments. We sought to compare the normal tissue dose received by children treated for HL and enrolled in the Childhood Cancer Survivor Study (CCSS) (diagnosed 1970-1986) with that of patients treated in recent Children's Oncology Group (COG) trials (enrolled 2002-2012).
  
  
  
  RT planning data were obtained for 50 HL survivors randomly sampled from the CCSS cohort and applied to computed tomography planning data sets to reconstruct the normal tissue dosimetry. For comparison, the normal tissue dosimetry data were obtained for all 191 patients with full computed tomography-based volumetric RT planning on COG protocols AHOD0031 and AHOD0831.
  
  
  
  For early-stage patients, the mean female breast dose in the COG patients was on average 83.5% lower than that for CCSS patients, with an absolute reduction of 15.5 Gy. For advanced-stage patients, the mean breast dose was decreased on average by 70% (11.6 Gy average absolute dose reduction). The mean heart dose decreased on average by 22.9 Gy (68.6%) and 17.6 Gy (56.8%) for early- and advanced-stage patients, respectively. All dose comparisons for breast, heart, lung, and thyroid were significantly lower for patients in the COG trials than for the CCSS participants. Reductions in the prescribed dose were a major contributor to these dose reductions.
  
  
  
  These are the first data quantifying the significant reduction in the normal tissue dose using actual, rather than hypothetical, treatment plans for children with HL. These findings provide useful information when counseling families regarding the risks of contemporary RT.
authors.affiliation: Department of Radiation Therapy, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors.forename: Rachel
authors.initials: R
authors.lastname: Zhou
authors.affiliation: Department of Radiation Therapy, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
authors.forename: Angela
authors.initials: A
authors.lastname: Ng
authors.affiliation: Department of Radiation Oncology, University of Rochester, Rochester, New York.
authors.forename: Louis S
authors.initials: LS
authors.lastname: Constine
authors.affiliation: Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Stovall
authors.affiliation: Epidemiology/Cancer Control Department, St. Jude Children's Research Hospital, Memphis, Tennessee.
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Armstrong
authors.affiliation: Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Neglia
authors.affiliation: Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Debra L
authors.initials: DL
authors.lastname: Friedman
authors.affiliation: Division of Pediatric Hematology/Oncology/Stem Cell Transplant, Department of Pediatrics, Columbia University Medical Center, New York, New York.
authors.forename: Kara
authors.initials: K
authors.lastname: Kelly
authors.affiliation: Department of Radiation Oncology, University of Massachusetts Medical School, Worcester, Massachusetts; Imaging and Radiation Oncology Core Group, Lincoln, Rhode Island.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: FitzGerald
authors.affiliation: Department of Radiation Oncology, University of Toronto, and Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada. Electronic address: David.hodgson@rmp.uhn.on.ca.
authors.forename: David C
authors.initials: DC
authors.lastname: Hodgson
mesh_terms: D001940:Breast / Q000528:radiation effects; D002986:Clinical Trials as Topic; D005260:Female; D006689:Hodgkin Disease / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D017741:Survivors