The usefulness of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with Langerhans cell histiocytosis.
OBJECTIVE
Langerhans cell histiocytosis (LCH) has a wide spectrum of clinical manifestations, ranging from spontaneous resolution to rapid progression or death, with the risk of permanent consequences. F-18 FDG PET/CT has been used for assessment of LCH patients. However, its clinical implication has not been well elucidated, mainly due to very low incidence of LCH. The aim of this study was to evaluate the clinical usefulness of F-18 FDG PET/CT in LCH patients.


METHODS
A database of 12 patients (mean age 17.8 ± 17.9 years; 7 children, 5 adults) who were diagnosed histopathologically as LCH was retrospectively reviewed. Two patients underwent F-18 FDG PET/CT before and after therapy, 6 patients underwent only before therapy and 4 patients underwent only after therapy.


RESULTS
Nine (75.0%) and 3 patients (25.0%) had single-system (single site and multiple sites) and multisystem involvements, respectively. Pretreatment SUV(max) of patients with multisystem or multiple site involvement of a single-system was significantly higher than that of patients with single site involvement of a single-system (3.29 ± 2.52 vs. 1.63 ± 0.52, p = 0.025). One patient showed multisystem risk organs (lung and bone marrow) involvement. In 2 patients, F-18 FDG PET/CT detected additional active LCH lesions not identified on conventional imaging modalities. In follow-up F-18 FDG PET/CT scans, complete resolution was identified in 2 patients and reactivation in another 2 patients.


CONCLUSIONS
Results of this study suggest that F-18 FDG PET/CT is useful for identification of active lesions, stratification of disease stages, monitoring of therapeutic response, and detection of reactivation in LCH patients.
Department of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences (DIRAMS), 40 Jwadong-gil, Jangan-eup, Gijang-gun, Busan, 619-953, South Korea.
Hong Je
HJ
Lee
Byeong-Cheol
BC
Ahn
Sang-Woo
SW
Lee
Jaetae
J
Lee
D000328:Adult; D002648:Child; D002675:Child, Preschool; D019788:Fluorodeoxyglucose F18; D006646:Histiocytosis, Langerhans-Cell / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
D019788:Fluorodeoxyglucose F18