title: Comparing Intelligence Quotient Change After Treatment With Proton Versus Photon Radiation Therapy for Pediatric Brain Tumors.
abstract: OBJECTIVE
  Compared with photon radiation (XRT), proton beam radiation therapy (PBRT) reduces dose to normal tissues, which may lead to better neurocognitive outcomes. We compared change in intelligence quotient (IQ) over time in pediatric patients with brain tumors treated with PBRT versus XRT.
  
  
  METHODS
  IQ scores were available for 150 patients (60 had received XRT, 90 had received PBRT). Linear mixed models examined change in IQ over time since radiation therapy (RT) by RT group, controlling for demographic/clinical characteristics. Craniospinal and focal RT subgroups were also examined.
  
  
  RESULTS
  In the PBRT group, no change in IQ over time was identified (P = .130), whereas in the XRT group, IQ declined by 1.1 points per year (P = .004). IQ slopes did not differ between groups (P = .509). IQ was lower in the XRT group (by 8.7 points) versus the PBRT group (P = .011). In the craniospinal subgroup, IQ remained stable in both the PBRT (P = .203) and XRT groups (P = .060), and IQ slopes did not differ (P = .890). IQ was lower in the XRT group (by 12.5 points) versus the PBRT group (P = .004). In the focal subgroup, IQ scores remained stable in the PBRT group (P = .401) but declined significantly in the XRT group by 1.57 points per year (P = .026). IQ slopes did not differ between groups (P = .342).
  
  
  CONCLUSIONS
  PBRT was not associated with IQ decline or impairment, yet IQ slopes did not differ between the PBRT and XRT groups. It remains unclear if PBRT results in clinically meaningful cognitive sparing that significantly exceeds that of modern XRT protocols. Additional long-term data are needed to fully understand the neurocognitive impact of PBRT in survivors of pediatric brain tumors.
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX. kahalley@bcm.edu.
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Kahalley
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: M Douglas
authors.initials: MD
authors.lastname: Ris
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: David R
authors.initials: DR
authors.lastname: Grosshans
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: M Fatih
authors.initials: MF
authors.lastname: Okcu
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Arnold C
authors.initials: AC
authors.lastname: Paulino
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Murali
authors.initials: M
authors.lastname: Chintagumpala
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Bartlett D
authors.initials: BD
authors.lastname: Moore
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Danielle
authors.initials: D
authors.lastname: Guffey
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Minard
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Heather H
authors.initials: HH
authors.lastname: Stancel
authors.affiliation: Lisa S. Kahalley, M. Douglas Ris, M. Fatih Okcu, Murali Chintagumpala, Danielle Guffey, Charles G. Minard, and Heather H. Stancel, Baylor College of Medicine, Houston; and David R. Grosshans, Arnold C. Paulino, Bartlett D. Moore, and Anita Mahajan, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Anita
authors.initials: A
authors.lastname: Mahajan
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D003071:Cognition / Q000528:radiation effects; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D007223:Infant; D007360:Intelligence / Q000528:radiation effects*; D007361:Intelligence Tests; D016014:Linear Models; D008297:Male; D017785:Photons / Q000009:adverse effects* / Q000627:therapeutic use; D061766:Proton Therapy; D011522:Protons / Q000009:adverse effects*; D012189:Retrospective Studies; D018401:Sample Size; D012959:Socioeconomic Factors; D016896:Treatment Outcome
chemical_list: D011522:Protons
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