Purpose: The aim of this retrospective study was to assess the value of 18F-FDG PET/CT in the initial evaluation and follow-up of patients with tuberculosis (TB).
Patients and methods: Thirty-five patients (18 men) with pulmonary or extrapulmonary TB were included. Diagnosis of TB was based either on histology or microbiological assessment in 32 patients and was based on typical morphological features of TB in CT and improvement on antimycobacterial medication in 3 patients. Eighty-eight 18F-FDG PET/CT scans were performed at initial assessment and during treatment, on a Siemens Biograph PET/CT. Diagnostic contrast-enhanced CT scans were performed on the 40-slice multidetector CT of the PET/CT scanner. Mean (SD) anti-TB treatment duration was 16.1 (8.9) months.
Results: The initial 18F-FDG PET identified 64 affected regions in 34 among 35 patients, whereas CT identified 34 affected organs in 23 patients. Matching image results between PET and CT were observed at first visit in 11 patients (31.4%), with relevant differences in 23 (65.7%). In 1 patient, both modalities remained negative. During follow-up 18F-FDG PET scans, we recorded 15 cases with remission of disease, 16 with residual disease (2 patients with multidrug-resistant infection), and 4 cases with progressive disease or delayed onset of adequate immunological response. In only 3 patients, both modalities, PET and CT, showed completely equivalent results.
Conclusions: Both components of 18F-FDG PET/CT provide complementary information at initial evaluation and during follow-up; however, 18F-FDG showed more abnormal findings than CT. 18F-FDG PET/CT might be useful for the establishment of individualized treatment regimes, but this requires further prospective studies.