Potential usefulness of 68Ga-citrate PET/CT in detecting infected lower limb prostheses

Abstract

BackgroundProsthetic joint infections may lead to failures of total joint arthroplasty. Radionuclide imaging can play a diagnostic role in identifying such infections, which require two-stage exchange arthroplasty (instead of simple revision surgery performed in non-infected cases). Although 18F-FDG PET/CT has emerged as a novel diagnostic tool in this setting, the clinical usefulness of 68Ga-citrate PET/CT has not been previously investigated. This single-center prospective study was designed to address this issue.MethodsBetween January 2016 and October 2017, we examined 34 patients with clinically proven or suspected prosthetic hip/knee joint infections scheduled to undergo surgery. All patients underwent 68Ga-citrate PET/CT scans and sequential 18F-FDG PET/CT imaging for comparative purposes. Intraoperative findings and the results of microbiological analyses of surgical specimens served as gold standard. The diagnostic results were examined according to (1) image interpretation based on radiotracer uptake patterns and (2) quantitative analysis using volumes of interest (VOIs) to calculate standard uptake values (SUVs) and metabolic volumes (MVs).ResultsA total of 26 (76%) patients were diagnosed as having infections. Based on radiotracer uptake pattern criteria, the sensitivity, specificity, and accuracy of 68Ga-citrate PET/CT and 18F-FDG PET/CT were 92%, 88%, and 91% and 100%, 38%, and 85%, respectively. MV was significantly higher in the infected group when 68Ga-citrate PET/CT was used (422.45 vs. 303.65 cm3, p = 0.027), whereas no significant differences were observed on 18F-FDG PET/CT. According to receiver operating characteristic (ROC) curve analysis, a cut-off value of 370.86 for MV resulted in a sensitivity of 61.5% and a specificity of 87.5% (area under curve: 0.75, 95% confidence interval: 0.57–0.88, p = 0.035).ConclusionsSubject to future confirmation, our data provide preliminary evidence that 68Ga-citrate PET/CT may have a complimentary role to 18F-FDG PET/CT in detecting prosthetic joint infections, being characterized by a higher specificity and the possibility to discriminate between an infectious condition and sterile inflammation.Trial registrationThis prospective study was registered at clinicaltrials.gov (registration number: NCT02855190).

Comparison of Fluorine(18)-fluorodeoxyglucose and Gallium(68)-citrate PET/CT in patients with tuberculosis

“…These findings are consistent with our finding that 68 Ga-citrate is less likely to accumulate in inflammatory lesions with no active infection compared to 18 F-FDG. Again, a more recent study found 68 Ga-citrate was more specific than 18 F-FDG in distinguishing infected lower limb prosthesis from sterile inflammation [26]. This critical role must be explored further due to the limited number of post-infective lesions we had in our study.…”

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

“…It has the advantages of high spatial resolution, good image quality, low radiation dose, and the potential for accurate anatomical localization [4,10,11]. Extensive literature has compared [ 18 F]FDG with [ 68 Ga]Ga-citrate for the diagnosis of bone infection-related diseases, and showed different results [13,16,17,27,28]. However, distinguishing bone infection from AL or physiological in ammation with [ 18 F]FDG remains challenging [4,9].…”

“…In addition, studies by Salomäki et al [17]. and Tseng et al [16]. have demonstrated that [ 18 F]FDG is unable to distinguish between bone infection and physiological healing or non-infectious complications after bone surgery.…”

“…Salomäki et al [17] demonstrated that [ 68 Ga]Ga-citrate was able to distinguish between bone infections and physiological bone healing following surgery to the bone. Data from Tseng et al [16] suggested that [ 68 Ga]Ga-citrate PET/CT may distinguish infectious from non-infectious diseases after joint replacement. However, research on the e cacy of [ 68 Ga]Ga-citrate PET/CT in distinguishing between PJI and AL is limited.…”

“…The purpose of this study was two-fold: (1) to evaluate any differences in the semi-quantitative analysis of the maximum SUV (SUVmax) of the target area, SUVmax of the target area/SUVmax of the non-target area (bone or muscle; T/NT [bone] and T/NT [muscle]) between PJI and AL; and (2) to compare the differential diagnostic performance of visual analysis and semi-quantitative analysis for PJI and AL. [16,18]: (1) a history of hip or knee arthroplasty; and (2) pain that was suspected to be due to PJI or AL and the patient was planned for treatment. The exclusion criteria of the study were as follows [16,18,19]: (1) the presence of another in ammatory arthropathy or osteopathy; (2) treatment with antibiotics before the study; 3infection or in ammation of other body parts; (4) critical illness or unstable vital signs; and (5) pregnancy or lactation.…”