title: Proton beam therapy for pediatric ependymoma.
abstract: BACKGROUND
  The aim of this study was to evaluate the efficacy of proton beam therapy for pediatric patients with ependymoma.
  
  
  METHODS
  Proton beam therapy was conducted for six patients (three boys and three girls; age, 2-6 years; median, 5 years) with ependymoma. The tumors were WHO grades 2 and 3 in two and four patients, respectively. All patients underwent surgery (subtotal and gross total resection in three patients each) and proton beam therapy at doses of 50.4-61.2 GyE (median, 56.7 GyE). The mean doses to normal brain tissue in proton beam therapy and photon radiotherapy were simulated using the same treatment planning computed tomography images.
  
  
  RESULTS
  All patients completed the planned irradiation. The follow-up period was 13-44 months (median, 24.5 months) from completion of proton beam therapy and all patients were alive at the end of this period. Local recurrence in the treatment field occurred in one patient at 4 months after proton beam therapy at 50.4 GyE. Alopecia and mild dermatitis occurred in all patients, but there was no severe toxicity. One patient had a once-off seizure after proton beam therapy and alopecia persisted in another patient for 31 months, but no patients had difficulty with daily life. The simulation showed that proton beam therapy reduces the dose to normal brain tissue by approximately half compared with photon radiotherapy.
  
  
  CONCLUSIONS
  Proton beam therapy for pediatric ependymoma is safe, does not have specific toxicities, and can reduce irradiation of normal brain tissue.
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizumoto
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.|Department of Radiation Oncology, Tsukuba Medical Center Hospital, Tsukuba, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Oshiro
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Takizawa
authors.affiliation: Department of Pediatrics, Tsukuba University, Tsukuba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukushima
authors.affiliation: Department of Pediatrics, Tsukuba University, Tsukuba, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Fukushima
authors.affiliation: Department of Neurosurgery, Tsukuba University, Tsukuba, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Neurosurgery, Tsukuba University, Tsukuba, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Muroi
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okumura
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuboi
authors.affiliation: Department of Radiation Oncology, Tsukuba University, Tsukuba, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Sakurai
mesh_terms: D002648:Child; D002675:Child, Preschool; D004806:Ependymoma / Q000175:diagnosis / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D061766:Proton Therapy / Q000379:methods; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: brain; ependymoma; pediatric; proton beam therapy; radiotherapy