title: Spatiotemporal Patterns of Tumor Occurrence in Children with Intraocular Retinoblastoma.
abstract: OBJECTIVE
  To accurately map the retinal area covered by tumor in a prospectively enrolled cohort of children diagnosed with retinoblastoma.
  
  
  METHODS
  Orbital MRI in 106 consecutive retinoblastoma patients (44 bilateral) was analyzed. For MRI-visible tumors, the polar angle and angle of eccentricity of points defining tumor perimeter on the retina were determined by triangulation from images in three orthogonal planes. The centroid of the mapped area was calculated to approximate tumor origin, and the location and cumulative tumor burden were analyzed in relation to mutation type (germline vs. somatic), tumor area, and patient age at diagnosis. Location of small tumors undetected by MRI was approximated with fundoscopic images.
  
  
  RESULTS
  Mapping was successful for 129 tumors in 91 eyes from 67 patients (39 bilateral, 43 germline mutation). Cumulative tumor burden was highest within the macula and posterior pole and was asymmetrically higher within the inferonasal periphery. Tumor incidence was lowest in the superotemporal periphery. Tumor location varied with age at diagnosis in a complex pattern. Tumor location was concentrated in the macula and superonasal periphery in patients <5.6 months, in the inferotemporal quadrant of the posterior pole in patients 5.6-8.8 months, in the inferonasal quadrant in patients 8.8-13.2 months, and in the nasal and superotemporal periphery in patients >13.2 months. The distribution of MRI-invisible tumors was consistent with the asymmetry of mapped tumors.
  
  
  CONCLUSIONS
  MRI-based mapping revealed a previously unrecognized pattern of retinoblastoma localization that evolves with age at diagnosis. The structured spatiotemporal distribution of tumors may provide valuable clues about cellular or molecular events associated with tumorigenesis in the developing retina.
authors.affiliation: Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, United States of America; Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: King
authors.affiliation: Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America; Department of Biomedical Engineering, University of Memphis, Memphis, Tennessee, United States of America.
authors.forename: Carlos
authors.initials: C
authors.lastname: Parra
authors.affiliation: Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Kathleen J
authors.initials: KJ
authors.lastname: Helton
authors.affiliation: Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Qaddoumi
authors.affiliation: Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, United States of America; Department of Surgery, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Wilson
authors.affiliation: Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ogg
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D019572:Retinal Neoplasms / Q000209:etiology / Q000473:pathology*; D012175:Retinoblastoma / Q000209:etiology / Q000473:pathology*