F-FDG Positron Emission Tomography in Patients with Concomi- tant Malignancy and Tuberculoma

Background: To analyze the result of F-FDG positron emission tomography (PET) in patients with a concomitant malignancy and tuberculoma in a tuberculosis (TB)-endemic area. Methods: Twelve patients with a concomitant malignancy and tuberculoma, who underwent whole-body F-FDG PET, were evaluated retrospectively. The maximal standardized uptake values (SUVmax) of the malignancy and tuberculoma were compared. In 6 patients, F-FDG PET was repeated during the anti-TB treatment and the changes in SUVmax were analyzed. Results: Of the 12 patients, 10 were male. The mean age was 67.2±7.9 years. Tuberculomas were located in the lung (n=10) and lymph nodes (n=2), and tumors were located in the lung (n=6), colon (n=3), stomach (n=1), ovary (n=1) and liver (n=1). Although the mean SUVmax of malignant lesions was higher than that of tuberculomas (5.2±3.2 vs 3.5±2.0), the difference was not significant. In 4 patients, the SUVmax was higher in the tuberculoma than the tumor. After anti-TB treatment in 6 patients, the mean SUVmax of the tuberculomas decreased significantly, from 3.5±2.0 to 1.6±0.9 (p=0.028). Conclusion: In patients with a concomitant malignancy and tuberculoma, SUVmax alone could not differentiate between them. However, F-FDG PET may be useful in monitoring the response to anti-TB treatment.