摘要Background Limited number of studies have been reported regarding the utilization of F-18-fluoro-deoxy-glucose (F-18-FDG) positron emission tomography/computed tomography (F-18-FDG PET/CT) in Langerhans cell histiocytosis (LCH).The aim of this study was to assess the role of F-18-FDG PET/CT in the diagnosis and treatment of LCH.Methods Eight newly diagnosed and seven recurrent patients with LCH received F-18-FDG PET/CT scans.The diagnosis of LCH was established by pathology,multi-modality imaging,and clinical follow-up.Results F-18-FDG PET/CT was positive in 14 patients with 13 true positives and one false positive.All 45 LCH lesions were F-18-FDG avid including six small bone lesions ＜1.0 cm in diameter.The mean maximal standardized uptake value (SUVmax) was 7.13±4.91.F-18-FDG uptake showed no significant difference between newly diagnosed lesions vs recurrent lesions (SUVmax:6.50±2.97 vs.7.93±6.60,t=-0.901,P=0.376).Among 45 LCH lesions,68.9％ (31/45) were found in bones and 31.1％ (14/45) in soft tissue.The most commonly involved bones were the pelvis and vertebrae.There was no significant difference in F-18-FDG uptake between bone lesions vs.non-bone lesions (SUVmax:6.30±2.87 vs.8.97±7.58,t=1.277,P=0.221).In two patients,changes in F-18-FDG uptake on serial PET/CT scans reflected response of lesions to treatment.Conclusions The present study suggests that F-18-FDG PET/CT may be useful for diagnosis and assessing the treatment response of LCH.Because of the small sample size,further research is warranted to confirm our findings.