Application of [68Ga]Ga-citrate PET/CT for Differentiating Prosthetic Joint Infection from Aseptic Loosening After Joint Replacement Surgery

Abstract Purpose Preoperative differentiation of prosthetic joint infection (PJI) and aseptic loosening (AL) is challenging. We aimed to evaluate the utility of visual analysis and semi-quantitative parameters of [68Ga]Ga-citrate positron emission tomography/computed tomography (PET/CT) in the differentiation of PJI and AL. Methods Sixteen patients with suspected PJI or AL underwent [68Ga]Ga-citrate PET/CT imaging. Results were evaluated by three nuclear medicine doctors based on (1) visual analysis of the attenuation correction (AC) and non-attenuation correction (NAC) based on tracer uptake intensity and range; (2) maximum standard uptake value (SUVmax) of lesions and the SUVmax of the target area/SUVmax of the non-target area (bone and muscle; T/NT [bone] and T/NT [muscle]). The final diagnosis was based on the Musculoskeletal Infection Society criteria, intraoperative findings, and histopathological and microbiological examinations. Results Overall, 10 (62.5%) and 6 (37.5%) patients were diagnosed with PJI and AL, respectively. Receiver operating characteristic analysis revealed that the areas under the curve for SUVmax, T/NT (bone), and T/NT (muscle) were 0.617 (cut-off = 2.243, P = 0.4312), 0.850 (cut-off = 2.844, P = 0.0052), and 0.850 (cut-off = 5.983, P = 0.0003), respectively. AC, NAC, and T/NT (bone) exhibited high differential diagnostic values (sensitivity, specificity, and accuracy of 90.0%, 83.3%, and 87.5%, respectively). The diagnostic efficacy of T/NT (muscle) was the second highest (sensitivity, specificity, and accuracy of 60.0%, 100%, and 75.0%, respectively). SUVmax demonstrated the poorest diagnostic efficacy (sensitivity, specificity, and accuracy of 70.0%, 66.7%, and 68.8%, respectively). Conclusion Our results suggest that [68Ga]Ga-citrate may differentiate PJI and AL.