title: External beam radiotherapy in retinoblastoma: tumor control and comparison of 2 techniques.
abstract: OBJECTIVE
  To investigate eye conservation, local control, and complication rates among children with retinoblastoma treated with 2 different external beam radiotherapy (EBR) techniques.
  
  
  METHODS
  Fifty-eight eyes in 42 patients received EBR as the primary treatment modality for retinoblastoma (median follow-up, 37 months). The EBR technique was relative lens-sparing (RLS) in 26 eyes and modified lateral beam (MLB) in 32 eyes. Both groups were comparable in Reese-Ellsworth retinoblastoma classification. If necessary, patients received focal salvage therapy.
  
  
  RESULTS
  At 24 months, eye conservation rates were 88.5% and 89.1% among eyes treated with RLS and MLB, respectively (P = .40); tumor control rates without salvage therapy were 84.6% and 53.3% (P = .02), respectively. Among eyes with Reese-Ellsworth stage IV and V disease, eye conservation rates were 88%+/-8% and 83%+/-9% at 36 months in the RLS and MLB groups, respectively, and local tumor control rates were 81%+/-10% and 51%+/-12%. Percentages of eyes without cataract at 36 months were 83.1% and 63.0%, respectively (P = .40). Among patients observed for at least 18 months, midfacial hypoplasia developed in 38.5% and 29.4%, respectively (P = .70).
  
  
  CONCLUSIONS
  The EBR technique was associated with high eye conservation and local control rates. Salvage therapy was performed significantly less frequently in the RLS group compared with the MLB group, and complication rates in both groups were similar.
authors.affiliation: Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, Fla 33136, USA.
authors.forename: I U
authors.initials: IU
authors.lastname: Scott
authors.forename: T G
authors.initials: TG
authors.lastname: Murray
authors.forename: W J
authors.initials: WJ
authors.lastname: Feuer
authors.forename: K
authors.initials: K
authors.lastname: Van Quill
authors.forename: A M
authors.initials: AM
authors.lastname: Markoe
authors.forename: S
authors.initials: S
authors.lastname: Ling
authors.forename: D B
authors.initials: DB
authors.lastname: Roth
authors.forename: J M
authors.initials: JM
authors.lastname: O'Brien
mesh_terms: D002675:Child, Preschool; D015353:Eye Enucleation; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D019572:Retinal Neoplasms / Q000145:classification / Q000473:pathology / Q000532:radiotherapy*; D012175:Retinoblastoma / Q000145:classification / Q000473:pathology / Q000532:radiotherapy*; D016879:Salvage Therapy; D016019:Survival Analysis; D016896:Treatment Outcome