title: Clinical outcomes of radiation therapy in the management of Langerhans cell histiocytosis.
abstract: OBJECTIVE
  Langerhans cell histiocytosis (LCH) is a rare disease with variable clinical presentation. In the present study, we report on the effectiveness and clinical complications of radiation therapy in children with LCH.
  
  
  METHODS
  We retrospectively reviewed all patients with LCH treated with radiation therapy over a 6-decade period at a single institution. Radiotherapy data, clinical features, radiographic data, and vital status were analyzed.
  
  
  RESULTS
  The mean age at diagnosis for 69 patients was 5.3 years (3 mo to 37 y) and the median duration of follow-up was 6 years (7 d to 32 y). Radiation therapy was performed for 169 sites, primarily bone lesions. The median radiotherapy dose was 10 Gy (2.5 to 45 Gy). Radiographic follow-up data were available for 139 of the sites treated and clinical follow-up was available for 156 of sites treated. The radiographic local control was 91.4%, and 13% of lesions showed complete sclerosis or reconstitution of bone. A total of 90.4% of patients reported stabilization or improvement in lesion-related symptoms, most often pain. Twelve patients had diabetes insipidus at diagnosis or during follow-up. Eight of these patients received radiation treatment to the pituitary and none experienced a reduction in desmopressin dosage posttreatment. Radiation complications were few, including femoral neck fracture in 1 patient and facial asymmetry in 3 patients. No secondary malignancies were observed.
  
  
  CONCLUSIONS
  Radiotherapy for LCH has high rates of local control and symptomatic improvement. Importantly, however, there is evidence of short-term and long-term morbidity when children are treated with low-dose irradiation.
authors: *Radiation Oncology Program †Division of Hematology/Oncology ‡Children's Orthopaedic Center, Children's Hospital Los Angeles §Keck School of Medicine, University of Southern California ∥Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA.
authors: Rupesh
authors: R
authors: Kotecha
authors: Rajkumar
authors: R
authors: Venkatramani
authors: Rima F
authors: RF
authors: Jubran
authors: Alexandre
authors: A
authors: Arkader
authors: Arthur J
authors: AJ
authors: Olch
authors: Kenneth
authors: K
authors: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D001842:Bone and Bones; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003919:Diabetes Insipidus / Q000209:etiology; D019468:Disease Management; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications / Q000532:radiotherapy*; D006801:Humans; D007223:Infant; D008297:Male; D010902:Pituitary Gland; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult