Significance of incidental focal FDG PET/CT uptake in the prostate gland: A systematic review and meta-analysis

Purpose: Given the variability in reported prostatic incidental fluorodeoxyglucose (FDG) uptake (PIU) rates and outcomes across recent studies, our analysis aims to clarify its clinical significance and explore potential predictive factors for malignancy. We systematically reviewed literature up to April 2025 to clarify PIU prevalence, risk factors, and characteristics. Materials and methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched databases for studies reporting PIU on fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Data extraction and bias assessment were done independently. Pooled analyses determined PIU prevalence, risk factors, and characteristics. Results: Among 2366 records, 17 met eligibility, with 14 for meta-analysis. PIU prevalence among 196,657 patients was 1.5% (95% confidence interval [CI], 1.1-2.0%), with substantial heterogeneity. Among further evaluated patients, 24.1% (95% CI, 17.4-32.3%) showed malignancy, while 56.0% (95% CI, 45.9-65.7%) of biopsied cases were malignant. Older age, elevated prostate-specific antigen (PSA), higher standardized uptake value, and peripheral zone FDG uptake were potential malignancy predictors. Conclusion: Our findings suggested that prostate-specific antigen, higher standardized uptake value, and peripheral uptake are key predictors of malignancy in PIU. Despite study limitations, standardized diagnostic criteria were proposed to improve diagnostic accuracy and patient outcomes in PIU management.