Role of 18F-FDG PET/CT in the diagnosis and management of patients with Langerhans cell histiocytosis

Zhe-Huang Luo; Pu-Xuan Lu; Wan-Lin Qi; Feng-Xiang Liao; Ai-Fang Jin; Qing-Yun Zen

doi:10.21037/qims-21-823

Role of ¹⁸F-FDG PET/CT in the diagnosis and management of patients with Langerhans cell histiocytosis

Quant Imaging Med Surg. 2022 Jun;12(6):3351-3363. doi: 10.21037/qims-21-823.

Authors

Zhe-Huang Luo^#¹, Pu-Xuan Lu^#², Wan-Lin Qi¹, Feng-Xiang Liao¹, Ai-Fang Jin¹, Qing-Yun Zen¹

Affiliations

¹ PET/CT Center, Jiangxi Provincial People's Hospital, Nanchang, China.
² Shenzhen Center for Chronic Disease Control, Shenzhen, China.

^# Contributed equally.

Abstract

Background: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm that can involve multisystem organs. Positron emission tomography/computed tomography (PET/CT) has been widely used in tumor staging and efficacy evaluation. However, at present, there are few ¹⁸F-fluorodeoxyglucose (FDG) PET/CT studies on LCH. This study aimed to explore the possible role of ¹⁸F-FDG PET/CT in the diagnosis and management of patients with LCH.

Methods: ¹⁸F-FDG PET/CT images of 22 Chinese patients diagnosed with LCH on biopsy or surgery histopathology between January 2011 and December 2020 were retrospectively analyzed. The incidence of LCH in each system was assessed by a PET/CT scan. The imaging characteristics were analyzed semiquantitatively and qualitatively. The discrepancies between PET/CT and conventional imaging modalities were recorded. Evaluations of curative effect according to RECIST1.1 and PERCIST1.0 were compared using Fisher's exact chi-squared test, and P values <0.05 were considered significant.

Results: Eight (36.4%) of the 22 patients presented with single system involvement (4 isolated site involvement, 4 multiple site involvement), and 14 (63.6%) presented with multiple system involvement. Twenty-one (95.5%) patients had hypermetabolic lesions. Musculoskeletal, lymphatic, respiratory, liver, skin-soft tissue and thyroid involvement were seen in 14 (63.6%), 13 (59.1%), 5 (22.7%), 4 (18.2%), 5 (22.7%) and 1 (4.5%) patient, respectively. Cranial and facial bones were the most common sites of musculoskeletal involvement. Ten patients underwent PET/CT follow-up, and there was no significant difference in curative effect evaluations according to RECIST1.1 and PERCIST1.0. However, among the complete remission cases assessed by RECIST1.1, three were partial metabolic responses assessed by PERCIST1.0, while among the partial response cases assessed by RECIST1.1, one was metabolic progressive disease assessed by PERCIST1.0.

Conclusions: ¹⁸F-FDG PET/CT is an imaging modality option for the diagnosis and assessment of the curative effect of LCH.

Keywords: 18F-fluorodeoxyglucose (FDG); Langerhans cell histiocytosis (LCH); evaluation of therapy efficiency; imaging manifestation; positron emission tomography/computed tomography (PET/CT).