title: Radiation therapy in management of sporadic and neurofibromatosis type 1-associated malignant peripheral nerve sheath tumors.
abstract: BACKGROUND
  Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft tissue sarcomas in which complete surgical resection is the mainstay of therapy. However, the recurrence rate is high and few options remain for refractory or metastatic MPNST. This study examines the outcomes of adjuvant radiation therapy in MPNST in patients with and without neurofibromatosis type 1 (NF1) and reviews the literature on use of radiation for MPNST.
  
  
  METHODS
  A retrospective review of 33 MPNST patients between 1990 and 2012 evaluated at the NIH. All diagnoses were pathologically confirmed at the NCI. Clinical presentation, treatment, and survival were analyzed.
  
  
  RESULTS
  Thirty-three patients were included 18 NF1-associated, 15 sporadic tumors. Tumor location included extremity (58%), trunk (36%), and head/neck (6%). Histologic grade showed 25 high-grade tumors compared to 7 low-grade tumors. Twenty patients were treated with radiation therapy (median total dose of 58.5 Gy with 1.8 Gy/fraction). A median survival of all patients was 46.5 months and 43.7% overall 5-year survival. Prognostic factors include extent of resection, tumor location, and histology grade. Radiation was not found to be a prognostic factor for overall survival.
  
  
  CONCLUSIONS
  This study is consistent with previous studies regarding the role of radiation in the management of MPNST. Prospective evaluation of adjuvant radiation will allow to more fully define the role of radiation in MPNST.
authors.affiliation: Radiation Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA ; Warren Alpert School of Medicine, Brown University , Providence, RI , USA.
authors.forename: Jenna
authors.initials: J
authors.lastname: Kahn
authors.affiliation: Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Andy
authors.initials: A
authors.lastname: Gillespie
authors.affiliation: Department of Pathology, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Tsokos
authors.affiliation: Radiation Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: John
authors.initials: J
authors.lastname: Ondos
authors.affiliation: Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Dombi
authors.affiliation: Radiation Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Camphausen
authors.affiliation: Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Brigitte C
authors.initials: BC
authors.lastname: Widemann
authors.affiliation: Radiation Oncology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD , USA.
authors.forename: Aradhana
authors.initials: A
authors.lastname: Kaushal
keywords: malignant peripheral nerve sheath tumor; malignant schwannoma; neurofibrosarcoma; neurogenic sarcoma; radiation therapy