18F-FDG PET/CT in tuberculosis: an early non-invasive marker of therapeutic response

OBJECTIVE: To evaluate the potential of F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) for early therapeutic intervention in patients with probable or confirmed tuberculosis (TB). METHODS: Twenty-one consecutive human immunodeficiency virus negative patients were prospectively included. All patients underwent F-18-FDG PET/CT before and after 1 month of anti-tuberculosis treatment. The maximum standardised uptake value (SUVmax) of the most F-18-FDG avid lesions was recorded. RESULTS: The median age of patients was 36 years (range 18-84); 33.3% were male, 80.9% were born in endemic countries, and 23.8% had a past history of TB. TB was confirmed on culture in 8, on histology in 9 and on the basis of clinical symptoms in 4 patients. F-18-FDG PET/CT detected active pulmonary TB (n = 1), extra-pulmonary (n = 10) or both (n = 10). The second F-18-FDG PET/CT showed reduced radiotracer uptake intensity in 19 of 21 patients, with a median percentage decrease of SUVmax of 31% (range 2-84). Two patients showed no improvement. TB was ruled out in one patient during follow-up; the final diagnosis was a non-Hodgkin's lymphoma. The other patient was smear-positive for 3 months. CONCLUSION: F-18-FDG PET/CT allows an easy evaluation of early therapeutic response in patients with TB, particularly extra-pulmonary TB.