title: 20-year experience with intraoperative high-dose-rate brachytherapy for pediatric sarcoma: outcomes, toxicity, and practice recommendations.
abstract: OBJECTIVE
  To assess outcomes and toxicity of high-dose-rate intraoperative radiation therapy (HDR-IORT) in the management of pediatric sarcoma.
  
  
  METHODS
  Seventy-five pediatric patients underwent HDR-IORT for sarcoma from May 1993 to November 2013. The median age was 9 years old (36 patients were ≤ 6 years old). HDR-IORT was part of initial therapy in 37 patients (49%) and for recurrent disease in 38 patients (51%). Forty-one patients (55%) received HDR-IORT and postoperative external beam RT (PORT), and 22 patients (29%) were previously treated with external beam radiation therapy to the IORT site. Local control (LC), overall survival (OS) and event-free survival (EFS) were estimated using Kaplan-Meier methods.
  
  
  RESULTS
  At a median follow-up of 7.8 years for surviving patients, 5-year projected rates of LC, EFS, and OS were 63% (95% confidence interval [CI] 50%-76%), 33% (95% CI 21%-45%), and 43% (95% CI 30%-55%), with a median survival of 3.1 years. The 5-year LC, EFS, and OS rates for patients with recurrent disease were 46% (95% CI, 28%-64%), 30% (95% CI, 13%-46%), and 36% (95% CI, 18%-54%). Acute toxicity ≥ grade 3 occurred in 2 (2.5%) treatments; late toxicity ≥ grade 3 occurred in 4 (5.3%) patients 0.3-9.9 years after HDR-IORT. The incidence of toxicity ≥ grade 3 was not associated with HDR-IORT applicator size, HDR-IORT dose, prior RT or PORT, or prior or postoperative chemotherapy, but all toxicity ≥ grade 3 occurred in patients ≤ 6 years treated with HDR-IORT doses ≥ 12 Gy.
  
  
  CONCLUSIONS
  HDR-IORT is a well-tolerated component of multimodality therapy for pediatric sarcoma, allowing additional local treatment while reducing external beam exposure. Taking clinical considerations into account, doses between 8-12 Gy are appropriate for HDR-IORT in patients ≤ 6 years of age.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Folkert
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: William Y
authors.initials: WY
authors.lastname: Tong
authors.affiliation: Department of Pediatric Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Michael P
authors.initials: MP
authors.lastname: LaQuaglia
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Wexler
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Chou
authors.affiliation: Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Heather
authors.initials: H
authors.lastname: Magnan
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York. Electronic address: woldens@mskcc.org.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Wolden
mesh_terms: D000293:Adolescent; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007432:Intraoperative Period; D012189:Retrospective Studies; D012509:Sarcoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult