title: Proton radiotherapy for pediatric Ewing's sarcoma: initial clinical outcomes.
abstract: OBJECTIVE
  Proton radiotherapy (PT) has been prescribed similarly to photon radiotherapy to achieve comparable disease control rates at comparable doses. The chief advantage of protons in this setting is to reduce acute and late toxicities by decreasing the amount of normal tissue irradiated. We report the preliminary clinical outcomes including late effects on our pediatric Ewing's sarcoma patients treated with PT at the Francis H. Burr Proton Therapy Center at Massachusetts General Hospital (Boston, MA).
  
  
  METHODS
  This was a retrospective review of the medical records of 30 children with Ewing's sarcoma who were treated with PT between April 2003 and April 2009.
  
  
  RESULTS
  A total of 14 male and 16 female patients with tumors in several anatomic sites were treated with PT at a median age of 10 years. The median dose was 54 Gy (relative biological effectiveness) with a median follow-up of 38.4 months. The 3-year actuarial rates of event-free survival, local control, and overall survival were 60%, 86%, and 89%, respectively. PT was acutely well tolerated, with mostly mild-to-moderate skin reactions. At the time of writing, the only serious late effects have been four hematologic malignancies, which are known risks of topoisomerase and anthracyline exposure.
  
  
  CONCLUSIONS
  Proton radiotherapy was well tolerated, with few adverse events. Longer follow-up is needed to more fully assess tumor control and late effects, but the preliminary results are encouraging.
authors.affiliation: ATreP (Provincial Agency for Proton Therapy), Trento, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Rombi
authors.forename: Thomas F
authors.initials: TF
authors.lastname: DeLaney
authors.forename: Shannon M
authors.initials: SM
authors.lastname: MacDonald
authors.forename: Mary S
authors.initials: MS
authors.lastname: Huang
authors.forename: David H
authors.initials: DH
authors.lastname: Ebb
authors.forename: Norbert J
authors.initials: NJ
authors.lastname: Liebsch
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Raskin
authors.forename: Beow Y
authors.initials: BY
authors.lastname: Yeap
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Marcus
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Tarbell
authors.forename: Torunn I
authors.initials: TI
authors.lastname: Yock
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016609:Neoplasms, Second Primary / Q000209:etiology; D058958:Organs at Risk / Q000528:radiation effects; D061766:Proton Therapy; D011522:Protons / Q000009:adverse effects; D011832:Radiation Injuries / Q000517:prevention & control; D011855:Radiodermatitis / Q000473:pathology; D011879:Radiotherapy Dosage; D012062:Relative Biological Effectiveness; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000401:mortality / Q000532:radiotherapy*; D015996:Survival Rate; D055815:Young Adult
chemical_list: D011522:Protons