title: Intraoperative Electron-Beam Radiation Therapy for Pediatric Ewing Sarcomas and Rhabdomyosarcomas: Long-Term Outcomes.
abstract: OBJECTIVE
  To assess long-term outcomes and toxicity of intraoperative electron-beam radiation therapy (IOERT) in the management of pediatric patients with Ewing sarcomas (EWS) and rhabdomyosarcomas (RMS).
  
  
  METHODS
  Seventy-one sarcoma (EWS n=37, 52%; RMS n=34, 48%) patients underwent IOERT for primary (n=46, 65%) or locally recurrent sarcomas (n=25, 35%) from May 1983 to November 2012. Local control (LC), overall survival (OS), and disease-free survival were estimated using Kaplan-Meier methods. For survival outcomes, potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model.
  
  
  RESULTS
  After a median follow-up of 72 months (range, 4-310 months), 10-year LC, disease-free survival, and OS was 74%, 57%, and 68%, respectively. In multivariate analysis after adjustment for other covariates, disease status (P=.04 and P=.05) and R1 margin status (P<.01 and P=.04) remained significantly associated with LC and OS. Nine patients (13%) reported severe chronic toxicity events (all grade 3).
  
  
  CONCLUSIONS
  A multimodal IOERT-containing approach is a well-tolerated component of treatment for pediatric EWS and RMS patients, allowing reduction or substitution of external beam radiation exposure while maintaining high local control rates.
authors.affiliation: Department of Radiation Oncology, Instituto de Radiomedicina, Santiago, Chile; School of Medicine, Complutense University, Madrid, Spain. Electronic address: csole@iram.cl.
authors.forename: Claudio V
authors.initials: CV
authors.lastname: Sole
authors.affiliation: School of Medicine, Complutense University, Madrid, Spain; Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Calvo
authors.affiliation: Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Polo
authors.affiliation: Service of Radiation Oncology, Clínica Universidad de Navarra, Pamplona, Spain.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Cambeiro
authors.affiliation: School of Medicine, Complutense University, Madrid, Spain; Service of Radiation Oncology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Gonzalez
authors.affiliation: School of Medicine, Complutense University, Madrid, Spain; Department of Experimental Surgery and Medicine, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Desco
authors.affiliation: Service of Radiation Oncology, Clínica Universidad de Navarra, Pamplona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Martinez-Monge
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods / Q000401:mortality; D018572:Disease-Free Survival; D004583:Electrons / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D060828:Induction Chemotherapy / Q000379:methods; D007430:Intraoperative Care; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D012208:Rhabdomyosarcoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D012512:Sarcoma, Ewing / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D013997:Time Factors; D055815:Young Adult