JNM: 68Ga-citrate PET/CT holds promise for evaluating bone infections
Preliminary data confirm a possible role for 68Ga-citrate in the diagnosis of bone infections, but more experience is required to further validate these results, according to a study published in the December issue of the Journal of Nuclear Medicine.

The study evaluated the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of 68Ga-citrate PET/CT in a population of patients with suspected bone infections, according to Cristina Nanni, MD, from the department of nuclear medicine at Azienda Ospedaliero–Universitaria di Bologna, Policlinico S. Orsola-Malpighi in Bologna, Italy and colleagues.

Nanni and colleagues enrolled 31 patients with suspected osteomyelitis or diskitis who underwent a total of forty 68Ga-citrate PET/CT scans. The results were compared with different combinations of diagnostic procedures (MRI, radiography, CT, or white blood cell scintigraphy), biopsy (when diagnostic), and follow-up data (at least one year) to determine the performance of 68Ga-citrate PET/CT.

Overall, the investigators found four false-positive scans using 68Ga-citrate PET/CT, 23 true-positive scans, 13 true-negative scans and no false-negative scans, resulting in a sensitivity of 100 percent, a specificity of 76 percent, a positive predictive value of 85 percent, a negative predictive value of 100 percent and an overall accuracy of 90 percent. Nanni and colleagues did not find significant tracer uptake in uninfected bone implants.

“According to our results, the performance of 68Ga-citrate PET/CT is not really superior to that of a conventional imaging diagnostic flow chart. Its added value basically relies on a simple and fast diagnostic procedure, the absence of contraindications to scanning, and low dosimetry due to the short half-life,” wrote Nanni and colleagues.

The short half-life of 68Ga-citrate, although an advantage from a dosimetric point of view, could be considered a drawback at the same time because it does not allow the long uptake time typical of 67Ga-citrate scintigraphy, added the authors.

“68Ga-citrate PET/CT is a new diagnostic tool that can be considered in the flow chart of patients with bone infection. However, more experience is required to further validate these results,” concluded Nanni and colleagues.