title: Development of a specific tracer for metabolic imaging of alveolar echinococcosis: A preclinical study.
abstract: Positron emission tomography (PET)-computed tomography (CT) using [18F]-fluorodeoxyglucose (FDG) (FDG-PET/CT) is a valuable method for initial staging and follow up of patients with alveolar echinococcosis (AE). However, the cells responsible for FDG uptake have not been clearly identified. The main goal of our study was to evaluate the uptake of PET tracers by the cells involved in the host-parasite reaction around AE lesions as the first step to develop a specific PET tracer that would allow direct assessment of parasite viability in AE. Candidate molecules ([18F]-fluorotyrosine (FET), [18F]-fluorothymidine (FLT), and [18F]-fluorometylcholine (FMC), were compared to FDG by in vitro studies on human leukocytes and parasite vesicles. Our results confirmed that FDG was mainly consumed by immune cells and showed that FLT was the best candidate tracer for parasite metabolism. Indeed, parasite cells exhibited high uptake of FLT. We also performed PET/CT scans in mice infected intraperitoneally with E. multilocularis metacestodes. PET images showed no FDG or FLT uptake in parasitic lesions. This preliminary study assessed the metabolic activity of human leukocytes and AE cells using radiolabeling. Future studies could develop a specific PET tracer for AE lesions to improve lesion detection and echinococcosis treatment in patients. Our results demonstrated that a new animal model is needed for preclinical PET imaging to better mimic human hepatic and/or periparasitic metabolism.
authors.forename: Clémence
authors.initials: C
authors.lastname: Porot
authors.forename: Jenny
authors.initials: J
authors.lastname: Knapp
authors.forename: Junhua
authors.initials: J
authors.lastname: Wang
authors.forename: Stéphane
authors.initials: S
authors.lastname: Germain
authors.forename: Davide
authors.initials: D
authors.lastname: Camporese
authors.forename: Yann
authors.initials: Y
authors.lastname: Seimbille
authors.forename: Hatem
authors.initials: H
authors.lastname: Boulahdour
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Vuitton
authors.forename: Bruno
authors.initials: B
authors.lastname: Gottstein
authors.forename: Oleg
authors.initials: O
authors.lastname: Blagosklonov
mesh_terms: D000818:Animals; D004443:Echinococcosis; D004444:Echinococcosis, Hepatic / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000469:parasitology; D019788:Fluorodeoxyglucose F18; D006801:Humans; D051379:Mice; D049268:Positron-Emission Tomography / Q000379:methods*; D011849:Radioactive Tracers; D014057:Tomography, X-Ray Computed
chemical_list: D011849:Radioactive Tracers; D019788:Fluorodeoxyglucose F18