Positron Emission Tomography in Patients with Concomitant Malignancy and Tuberculoma

Background: To analyze the result of $^{18}F-FDG$ 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 $^{18}F-FDG$ PET, were evaluated retrospectively. The maximal standardized uptake values (SUVmax) of the malignancy and tuberculoma were compared. In 6 patients, $^{18}F-FDG$ 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 $67.2{\pm}7.9$ 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 ($5.2{\pm}3.2$ vs $3.5{\pm}2.0$), 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 $3.5{\pm}2.0$ to $1.6{\pm}0.9$ (p=0.028). Conclusion: In patients with a concomitant malignancy and tuberculoma, SUVmax alone could not differentiate between them. However, $^{18}F-FDG$ PET may be useful in monitoring the response to anti-TB treatment.