Diagnostic contribution of positron emission tomography with [18F]fluorodeoxyglucose for invasive fungal infections
Résumé
Optimal staging and evaluation of residual lesions of invasive fungal infections (IFIs) are major challenges in the immunocompromised host. Preliminary data have suggested that [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) uptake may be observed in the course of active inva-sive fungal infections. The aim of this study was to assess the role of positron emission tomography with [ 18 F]FDG ([ 18 F]FDG-PET) in the diagnosis and staging of IFI. A prospective monocentric study evaluating [ 18 F]FDG-PET in 30 consecutive adults and children with European Organization for Research and Treatment of Cancer/Mycoses Study Group probable or proven IFI was performed. Twenty males and ten females (median age, 45 years (range 6-75 years)) were enrolled. Twenty-six were immunocompromised, as follows: haematological malignancy (18) with allogeneic stem cell transplantation (16/18), solid tumour (three), solid organ transplanta-tion (two), diabetes mellitus (two) and cystic fibrosis (one). IFIs were acute invasive aspergillosis (ten), chronic disseminated candidia-sis (ten), zygomycosis (two), black grains eumycetoma (two), pulmonary Histoplasma capsulatum var. capsulatum histoplasmosis (two), and Phomopsis sp. osteoarthritis, Scedosporium apiospermum and Candida krusei spondylodiscitis, and acute pulmonary coccidioidomyco-sis in one case each. An increased uptake of [ 18 F]FDG was observed in all areas previously identified by computed tomography and/ or magnetic resonance imaging to be involved by IFI. In 4/10 chronic disseminated candidiasis cases, [ 18 F]FDG-PET revealed small splenic abscesses that were unapparent on the corresponding computed tomography scan. [ 18 F]FDG uptake disappeared after 6 months of antifungal therapy in three patients with chronic disseminated candidiasis for whom the [ 18 F]FDG-PET was performed to assess the evolution of the disease. [ 18 F]FDG-PET could potentially be useful for the initial diagnosis and staging of IFI. Whether or not [ 18 F]FDG-PET might be useful for assessing the optimal duration of IFI therapy should now be assessed in a specific prospective study.