68Ga-Citrate-PET for Diagnostic Imaging of Infection in Rats and for Intra-Abdominal Infection in a Patient

Vijay      Kumar; Dilip      K. Boddeti; Scott      G. Evans; Socrates      Angelides

doi:10.2174/1874471011205010071

Abstract

Objectives: ⁶⁷Ga-Citrate has been extensively used for infection and inflammation imaging for the past four decades but has limitations. In the present study, we explored the ability of ⁶⁸Ga-Citrate to detect Staphylococcus aureus (Staph A) infection in rats and further studied its ability to localize intra-abdominal infection in a patient.

Methods: An infection was induced in male Wistar rats by injecting Staph A in the right thigh muscle. In this study a simple method was described for the preparation of ⁶⁸Ga-Citrate with > 99% yield and purity. ⁶⁸Ga-Citrate (15 MBq/rat and 150 MBq/patient) was injected intravenously and the images were acquired for 10 min each.

Results: ⁶⁸Ga-Citrate uptake was moderate at the infection lesion within 5 min post injection but intense focal uptake was visualized from 30 min to 6 hr post-injection in rats. Cardiac blood pool and liver activity decreased during the same period of study. In the patient studied, an infected area in the abdomen at the site of recent appendectomy was detected within 30min post-injection of ⁶⁸Ga-Citrate, which was consistent with CT and microbiology findings.

Conclusion: A simple method of preparation of ⁶⁸Ga-Citrate with > 99% yield and purity was described, suitable for routine clinical work. Our results showed ⁶⁸Ga-Citrate is capable of detecting Staph A infection in rats and an intraabdominal infection in a post-operative patient. These findings indicate the high potential of ⁶⁸Ga-Citrate for clinical utility.

Keywords: Abdominal infection, ⁶⁸Ga-Citrate PET for infection imaging, Staphylococcus aureus, ⁶⁸Ga-PET, ⁶⁸Ga-Citrate, 68Ge/68Ga Generator, SPET