Evaluation of 18F-FDG PET/CT in extrapulmonary tuberculosis: Preliminary results of an observational pilot study

Aim. Extrapulmonary tuberculosis treatment is difficult to assess and there is a need for new tools. The aim of this observational pilot study is to evaluate the potential role of 18F-FDG PET/CT in the initial staging and treatment evaluation of extrapulmonary tuberculosis. Methods. Twenty-eight patients were included between January 2009 and 2010. Twenty-three had a 18F-FDG PET/CT before treatment and/or during and/or after treatment. All patients will be followed for 18 months after the end of treatment. A control group of five patients with previous history of tuberculosis was also included and PET/CT was performed. Results. Three cases of differential diagnosis were excluded of the study. The initial PET for staging showed additional lesions in 8/10 patients compared to conventional imaging. At the end of treatment, 6/11 patients had a negative PET, and 5/11 patients had a positive PET. PET had a significant clinical impact for 3/10 patients at initial staging (guiding biopsy or increase of planned treatment duration), and for 3/16 during follow up (extend or early interruption of the treatment). All PET scans in the control group were negative. Conclusion. 18F-FDG PET has an excellent sensitivity for the detection of extrapulmonary tuberculosis lesion and excellent negative predictive values. The impact of initial PET staging seems significant. The interest of 18F-FDG PET for the evaluation of response to treatment remains to be assessed and will be correlated with patients' follow up in a second phase of this study. (C) 2011 Elsevier Masson SAS. All rights reserved.