title: 18F-fluorodeoxyglucose positron emission tomography-computed tomography in the management of adult multisystem Langerhans cell histiocytosis.
abstract: OBJECTIVE
  The standard evaluation of multisystem Langerhans cell histiocytosis (LCH) includes a clinical evaluation, laboratory tests and a skeleton/skull X-ray survey, with chest high-resolution computed tomography (HRCT) in the case of pulmonary involvement. Preliminary reports suggest that18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) may be useful for evaluating patients with LCH.
  
  
  METHODS
  Fourteen consecutive adult patients with multisystem LCH were included in this retrospective study, and were evaluated using standard procedures and18F-FDG PET-CT. The two sets of findings were compared both at baseline and during follow-up. Serial HRCT and pulmonary function tests were used to evaluate outcome in patients with lung involvement.
  
  
  RESULTS
  At the baseline evaluation, PET-CT identified every LCH localization found with the standard evaluation (except a mild cecum infiltration). PET-CT showed additional lesions in seven patients, mostly involving bones, and differentiated inactive from active lesions. Thyroid18F-FDG uptake was identified in three cases. No pituitary stalk18F-FDG uptake was observed in patients with pituitary LCH. Only 3/12 (25 %) patients with pulmonary LCH displayed moderate pulmonary18F-FDG uptake. During follow-up, variations (≥50 % of maximum standardized uptake) in bone18F-FDG uptake intensity were correlated with disease state and response to treatment. The absence of lung18F-FDG uptake did not preclude lung function improvement after treatment.
  
  
  CONCLUSIONS
  Except for cases with pulmonary and pituitary involvement,18F-FDG PET-CT could replace the standard evaluation for staging of adult patients with multisystem LCH. Serial PET-CT scans are useful for evaluating treatment responses, particularly in cases with bone LCH involvement.
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Paris, France.|Centre National de Référence de l'Histiocytose Langerhansienne, Service de Pneumologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Obert
authors.affiliation: Service de Médecine Nucléaire, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Vercellino
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Paris, France.|Service de Médecine Nucléaire, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Van Der Gucht
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Paris, France.|Service de Radiologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Constance
authors.initials: C
authors.lastname: de Margerie-Mellon
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Service de Pneumologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Bugnet
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Paris, France.|Service de Biostatistique et Information Médicale, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.|U1153 CRESS, Biostatistics and Clinical Epidemiology Research Team, Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chevret
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Service de Pneumologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Gwenaël
authors.initials: G
authors.lastname: Lorillon
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Paris, France. abdellatif.tazi@aphp.fr.|Centre National de Référence de l'Histiocytose Langerhansienne, Service de Pneumologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France. abdellatif.tazi@aphp.fr.|U1153 CRESS, Biostatistics and Clinical Epidemiology Research Team, Paris, France. abdellatif.tazi@aphp.fr.
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Tazi
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D019788:Fluorodeoxyglucose F18; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000000981:diagnostic imaging; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals; D013961:Thyroid Gland / Q000000981:diagnostic imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Langerhans cell histiocytosis; Management; PET-CT; Response to treatment