title: Proton therapy for spinal ependymomas: planning, acute toxicities, and preliminary outcomes.
abstract: OBJECTIVE
  To report acute toxicities and preliminary outcomes for pediatric patients with ependymomas of the spine treated with proton beam therapy at the MD Anderson Cancer Center.
  
  
  METHODS
  Eight pediatric patients received proton beam irradiation between October 2006 and September 2010 for spinal ependymomas. Toxicity data were collected weekly during radiation therapy and all follow-up visits. Toxicities were graded according to the Common Terminology Criteria for Adverse Events version 3.0.
  
  
  RESULTS
  All patients had surgical resection of the tumor before irradiation (7 subtotal resection and 1 gross total resection). Six patients had World Health Organization Grade I ependymomas, and two had World Health Organization Grade II ependymomas. Patients had up to 3 surgical interventions before radiation therapy (range, 1-3; median, 1). Three patients received proton therapy after recurrence and five as part of their primary management. The entire vertebral body was treated in all but 2 patients. The mean radiation dose was 51.1 cobalt gray equivalents (range, 45 to 54 cobalt gray equivalents). With a mean follow-up of 26 months from the radiation therapy start date (range, 7-51 months), local control, event-free survival, and overall survival rates were all 100%. The most common toxicities during treatment were Grade 1 or 2 erythema (75%) and Grade 1 fatigue (38%). No patients had a Grade 3 or higher adverse event. Proton therapy dramatically reduced dose to all normal tissues anterior to the vertebral bodies in comparison to photon therapy.
  
  
  CONCLUSIONS
  Preliminary outcomes show the expected control rates with favorable acute toxicity profiles. Proton beam therapy offers a powerful treatment option in the pediatric population, where adverse events related to radiation exposure are of concern. Extended follow-up will be required to assess for late recurrences and long-term adverse effects.
authors.affiliation: Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Amsbaugh
authors.forename: David R
authors.initials: DR
authors.lastname: Grosshans
authors.forename: Mary Frances
authors.initials: MF
authors.lastname: McAleer
authors.forename: Ron
authors.initials: R
authors.lastname: Zhu
authors.forename: Cody
authors.initials: C
authors.lastname: Wages
authors.forename: Cody N
authors.initials: CN
authors.lastname: Crawford
authors.forename: Matthew
authors.initials: M
authors.lastname: Palmer
authors.forename: Beth
authors.initials: B
authors.lastname: De Gracia
authors.forename: Shiao
authors.initials: S
authors.lastname: Woo
authors.forename: Anita
authors.initials: A
authors.lastname: Mahajan
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D004806:Ependymoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004890:Erythema / Q000209:etiology / Q000473:pathology; D005221:Fatigue / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D061766:Proton Therapy; D011522:Protons / Q000009:adverse effects; D011832:Radiation Injuries; D011879:Radiotherapy Dosage; D013125:Spinal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D011522:Protons