title: Proton radiation therapy for the treatment of retinoblastoma.
abstract: OBJECTIVE
  To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT).
  
  
  METHODS
  This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012.
  
  
  RESULTS
  The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy.
  
  
  CONCLUSIONS
  Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.
authors.affiliation: Harvard Radiation Oncology Program, Boston, Massachusetts; Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Kent W
authors.initials: KW
authors.lastname: Mouw
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Roshan V
authors.initials: RV
authors.lastname: Sethi
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Beow Y
authors.initials: BY
authors.lastname: Yeap
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: MacDonald
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Yen-Lin E
authors.initials: YL
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Tarbell
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Torunn I
authors.initials: TI
authors.lastname: Yock
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: John E
authors.initials: JE
authors.lastname: Munzenrider
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Judith
authors.initials: J
authors.lastname: Adams
authors.affiliation: Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Eric
authors.initials: E
authors.lastname: Grabowski
authors.affiliation: Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.
authors.forename: Shizuo
authors.initials: S
authors.lastname: Mukai
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts. Electronic address: hshih@partners.org.
authors.forename: Helen A
authors.initials: HA
authors.lastname: Shih
mesh_terms: D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods*; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D019572:Retinal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D012175:Retinoblastoma / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity