Utility of Tc-99m-labeled levofloxacin as an infection-imaging agent in musculoskeletal infections.

Background: The purpose of this study is to ascertain the utility of Technetium (Tc)-99m-labeled levofloxacin in diagnosing musculoskeletal infections and also to observe its biodistribution in the human body. Patients who were referred with the clinical suspicion of having osteomyelitis underwent Tc-99m levofloxacin imaging. Methods: Tc-99m-labeled levofloxacin scintigraphy was carried out in 30 patients with musculoskeletal infections and the results were compared with the culture and sensitivity of suspected lesions. Results: Fifteen patients were true-positive, 2 were false-positive, 1 was false-negative, and 12 were true-negative. The sensitivity and specificity were 93.8% and 85.7%, respectively. The positive and negative predictive values were 88.2% and 92.3%, respectively. The biodistribution studies revealed that 7.74% ± 0.42% of the injected dose at 1 hour decreased to 5.45% ± 0.37% at 2 hours, and to 2.49% ± 0.55% at 4 hours. The liver showed a mean uptake value of 5.58% of injected activity at 1 hour, which decreased to 3.52% ± 0.30% and 2.00% ± 0.5 0% at 2 and 4 hours, respectively. The activity in the bladder increased from the mean percentage uptake value of 5.45% ± 0.84% at 1 hour to 20.00% ± 3.67% at 2 hours and 39.67% ± 4.23% at 4 hours. The results of Student's t-test showed significant differences in the uptake values of infected and noninfected sites. Chi-square results confirmed strong association between osteomyelitis and Tc 99m Levofloxacin uptake. Conclusion: Tc-99m-labeled levofloxacin has the potential of simulating an infection-imaging agent. [ABSTRACT FROM AUTHOR]