title: Outcomes and acute toxicities of proton therapy for pediatric atypical teratoid/rhabdoid tumor of the central nervous system.
abstract: OBJECTIVE
  Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a rare cancer primarily affecting children younger than 5 years old. Because patients are young and receive intensive chemotherapy, there is concern regarding late radiation toxicity, particularly as survival rates improve. Therefore, there is interest in using proton therapy to treat these tumors. This study was undertaken to investigate outcomes and acute toxicities associated with proton therapy for AT/RT.
  
  
  METHODS
  The records of 31 patients with AT/RT treated with proton radiation from October 2008 to August 2013 were reviewed. Demographics, treatment characteristics, and outcomes were recorded and analyzed.
  
  
  RESULTS
  Median age at diagnosis was 19 months (range, 4-55 months), with a median age at radiation start of 24 months (range, 6-62 months). Seventeen patients received local radiation with a median dose of 50.4 GyRBE (range, 9-54 GyRBE). Fourteen patients received craniospinal radiation; half received 24 GyRBE or less, and half received 30.6 GyRBE or more. For patients receiving craniospinal radiation, the median tumor dose was 54 GyRBE (range, 43.2-55.8 GyRBE). Twenty-seven patients (87%) completed the planned radiation. With median follow-up of 24 months for all patients (range, 3-53 months), median progression-free survival was 20.8 months and median overall survival was 34.3 months. Five patients (16%) developed clinical findings and imaging changes in the brainstem 1 to 4 months after radiation, consistent with radiation reaction; all cases resolved with steroids or bevacizumab.
  
  
  CONCLUSIONS
  This is the largest report of children with AT/RT treated with proton therapy. Preliminary survival outcomes in this young pediatric population are encouraging compared to historic results, but further study is warranted.
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas. Electronic address: slmcgove@mdanderson.org.
authors.forename: Susan L
authors.initials: SL
authors.lastname: McGovern
authors.affiliation: Texas Children's Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas.
authors.forename: M Fatih
authors.initials: MF
authors.lastname: Okcu
authors.affiliation: Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Munsell
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Nancy
authors.initials: N
authors.lastname: Kumbalasseriyil
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: David R
authors.initials: DR
authors.lastname: Grosshans
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Mary F
authors.initials: MF
authors.lastname: McAleer
authors.affiliation: Texas Children's Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas.
authors.forename: Murali
authors.initials: M
authors.lastname: Chintagumpala
authors.affiliation: Department of Pediatrics, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Soumen
authors.initials: S
authors.lastname: Khatua
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Anita
authors.initials: A
authors.lastname: Mahajan
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D001933:Brain Stem / Q000528:radiation effects*; D016543:Central Nervous System Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D002675:Child, Preschool; D061888:Craniospinal Irradiation / Q000009:adverse effects* / Q000379:methods; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D061766:Proton Therapy / Q000009:adverse effects* / Q000379:methods; D011832:Radiation Injuries / Q000188:drug therapy / Q000473:pathology; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D018335:Rhabdoid Tumor / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D013724:Teratoma / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab