Role of 18F-FDG PET/CT in Renal Cyst Infection

Diagnostic Performance of 18-Fluorodeoxyglucose Positron-Emission Tomography-Computed Tomography (18F-FDG PET-CT) in the Detection of Autosomal Dominant Polycystic Kidney Disease Cyst Infections: A Meta-Analysis

Diagnosing suspected renal or hepatic infections in autosomal dominant polycystic kidney disease (ADPKD) is difficult. Although 18-fluorodeoxyglucose positron-emission tomography-computed tomography (18F-FDG PET-CT) is recommended to aid in the diagnosis, there is no consensus about its diagnostic accuracy. We aimed to investigate its diagnostic performance. To further assess this, we performed a meta-analysis. A comprehensive literature search screening of PubMed/MEDLINE, Embase, and Cochrane library databases through February 2024 was performed. Pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and C-reactive protein (CRP) were estimated using the random effects model. Heterogeneity between studies was estimated using Cochran Q and I2 statistics. A total of seven studies were included in the final analysis. The pooled sensitivity of 18F-FDG PET-CT in diagnosing kidney and hepatic cyst infection was 82.6% (95% CI: 73.8-88.9; I2 16.9%), specificity was 77.6% (95% CI: 66.7-85.7; I2 15.6%), PPV was 79.4% (95% CI: 62.4-89.9; I2 62.6%), and NPV was 81.3% (95% CI: 72.7-87.7; I2 0%). The mean CRP was 244.2 mg/L (95% CI: 209.1-279.1; I2 66%). The results showed that 18F-FDG PET-CT demonstrated excellent pooled diagnostic performance in diagnosing renal and hepatic cyst infections in ADPKD.

Radiosynthesis Standardization and Preclinical Assessment of the [68Ga]Ga-DOTA-Ubiquicidin29-41: A Translational Study Targeting Differential Diagnosis of Infectious Processes

Human bacterial infections significantly contribute to the increase in healthcare-related burdens. This scenario drives the study of novel techniques for the early and precise diagnosis of infectious processes. Some alternatives include Nuclear Medicine- and Molecular Imaging-based strategies. However, radiopharmaceuticals that are available for routine assessments are not specific to differentiating infectious from aseptic inflammatory processes. In this context, [68Ga]Ga-DOTA-Ubiquicidin29-41 was synthesized using an automated module and radiochemical; in vivo and in vitro studies were performed. The radiopharmaceutical remained stable in saline (up to 180 min) and in rodent serum (up to 120 min) with radiochemical purities > 99 and 95%, respectively. Partition coefficient and serum protein binding at 60 min were determined (-3.63 ± 0.17 and 44.06 ± 1.88%, respectively). Ex vivo biodistribution, as well as in vivo microPET/CT images in mice, showed rapid blood clearance with renal excretion and reduced uptake in other organs in Staphylococcus aureus-infected animals. Higher uptake was observed in the target as compared to the non-target tissue (p < 0.0001) at 60 min post administration. The presented in-human clinical case demonstrates uptake of the radiopharmaceutical by Staphyloccocus aureus bacteria. These results indicate the potential of [68Ga]Ga-DOTA-Ubiquicidin29-41 as a radiopharmaceutical that can be obtained in a hospital radiopharmacy for the diagnosis of infectious processes using PET/CT.