title: 18F-FDG PET/CT in follow-up evaluation in pediatric patients with Langerhans histiocytosis.
abstract: OBJECTIVE
  We evaluated the impact of18F-FDG PET/CT in identifying sites of active disease and to assess therapeutic follow up in a group of pediatric patients with Langerhans cell histiocytosis (LCH).
  
  
  METHODS
  During 2007-2013, 1318F-FDG PET/CT studies were performed for follow-up in 7 patients with a diagnosis of LCH (4 female, 3 male; 1-12 years-old). PET findings were analyzed and correlated with the CT and MRI. Findings were also follow-up by these techniques.
  
  
  RESULTS
  PET was negative in 4 patients (all diagnosed with bone lesions and one with pituitary involvement also). CT findings showed residual morphological bone lesions in all patients, and hypophysis MRI study showed no abnormal signal. PET remained negative at 10, 14, 25 and 28 months, and no new lesions on CT and MRI were detected. PET was positive in 3 patients (one with cervical lymphadenopathy and 2 with bone lesions, one also with pituitary involvement not identified by PET). CT findings showed pathological cervical lymphadenopathy (n=1), bone lesions (n=2) and also a pituitary MRI lesion (n=1). In a patient with cervical lymphadenopathy histology demonstrated LCH involvement. In the other 2 patients, PET remained positive with an increase of18F-FDG bone uptake at 17 and 19 months.
  
  
  CONCLUSIONS
  In our preliminar study,18F-FDG PET is a useful imaging procedure, along with other diagnostic tools, for identification of active lesions.
authors.affiliation: Unidad PET, CETIR-ERESA, Esplugues de Llobregat, Barcelona, España. Electronic address: jrgarcia@cetir.es.
authors.forename: J R
authors.initials: JR
authors.lastname: Garcia
authors.affiliation: Unidad PET, CETIR-ERESA, Esplugues de Llobregat, Barcelona, España.
authors.forename: E
authors.initials: E
authors.lastname: Riera
authors.affiliation: Unidad PET, CETIR-ERESA, Esplugues de Llobregat, Barcelona, España.
authors.forename: P
authors.initials: P
authors.lastname: Bassa
authors.affiliation: Unidad PET, CETIR-ERESA, Esplugues de Llobregat, Barcelona, España.
authors.forename: S
authors.initials: S
authors.lastname: Mourelo
authors.affiliation: Unidad PET, CETIR-ERESA, Esplugues de Llobregat, Barcelona, España.
authors.forename: M
authors.initials: M
authors.lastname: Soler
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D007223:Infant; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDG PET/CT; Histiocitosis de Langerhans; Langerhans histiocytosis; PET/TC con (18)F-FDG