Prospective Serial FDG PET/CT During Treatment of Extrapulmonary Tuberculosis in HIV-Infected Patients: An Exploratory Study

PURPOSE: The aim of this study was to prospectively describe evolution of F-FDG uptake of extrapulmonary tuberculosis (TB) throughout the course of TB treatment in HIV patients to evaluate F-FDG PET/CT as a monitoring tool of treatment response. METHODS: We performed baseline FDG PET/CT, PET-2 after 2 months, and PET-3 at the end of TB treatment in 18 HIV/TB patients. We correlated evolution of FDG uptake with clinical outcome of patients. RESULTS: After 2 months of treatment, 78% of the patients had a significant metabolic response. Lymph node (LN) metabolic response was heterogeneous, with 57% of LN sites showing decreased SUVmax and 41% showing unchanged FDG uptake. Organs other than LNs showed more homogeneous response. The FDG PET/CT performed at the end of TB treatment showed a complete response of all infected organs and a drastic response in terms of active LNs in 95% of the patients (SUVmax mean decrease = 85%, median = 100%). A complete metabolic response after TB treatment was seen in only 47% of patients. CONCLUSIONS: In difficult-to-treat entities such as extrapulmonary TB in HIV patients, FDG PET/CT is a potential tool in monitoring TB treatment response and should be explored in larger studies.