Dual-Tracer Positron-Emission Tomography Using Prostate-Specific Membrane Antigen and Fluorodeoxyglucose for Staging of Prostate Cancer: A Systematic Review

Table 1

Summary of included cohort studies, comprising prospective trials and retrospective analyses, across the spectrum of prostate cancer (PCa) including primary staging, biochemical recurrence (BCR), hormone-sensitive PCa (HSPCa), and castrate-resistant PCa (CRPCa).

Category	N	Study	N	Criteria	Characteristics	Findings
Primary staging	86	Zhou et al. [30]	21	(i) No prior treatment	Median PSA: 41.2 ng/mL; 53% ISUP ≥4	PSMA PET/CT identified more bone (50 vs. 32) and lymph node (25 vs. 22) metastases, with less benign lesions (21% vs. 49%) than FDG PET
		Shi et al. [31]	65	(i) No treatment between PSMA and FDG PET/CT; (ii) <2 weeks of interval in imaging	Median PSA: 56.4 ng/ml	PSMA/FDG PET detected N+ when both are avid (PSMA SUVmax >2.05 and FDG SUVmax >4.1; n = 43/47, 92%) compared to low or no avidity (PSMA SUVmax <2.05 and FDG SUVmax <4.1; n = 3/334, 1%); 83 PSMA-avid lymph nodes (primary + BCR) with FDG uptake in 53% (n = 52/83); No association between the PSA level and PSMA or FDG uptake in ganglia or lymph node metastases in primary staging
BCR	159	Chen et al. [32]	72	(i) PSA >0.2 ng/ml after RP; (ii) Not on androgen deprivation; (iii) N0M0 on Ga68 PSMA PET/CT	Median PSA: 0.5 ng/mL; 44% ISUP ≥4; 38% prior adjuvant ADT	FDG-avid disease found in 17% of patients with negative PSMA PET/CT
		Shi et al. [31]	73	(i) No treatment between PSMA and FDG PET/CT; (ii) <2 weeks of interval in imaging	Median PSA: 1.1 ng/mL	PSMA/FDG PET detected N+ when both are avid (PSMA SUVmax >2.05 and FDG SUVmax >4.1; n = 43/47, 92%) compared to low or no avidity (PSMA SUVmax <2.05 and FDG SUVmax <4.1; n = 3/334, 1%); 83 PSMA-avid lymph nodes (primary + BCR) with FDG uptake in 53% (n = 52/83); No association between the PSA level and PSMA or FDG uptake in ganglia or lymph node metastases in BCR
		Wang et al. [33] (retrospective)	14	(i) Not defined	Median PSA: 0.35 ng/mL; 50% ISUP ≥4; 100% after RP	0% with PSMA− FDG+ lesions
HSPCa	18	Wang et al. [33] (retrospective)	18	(i) Not defined	Median PSA: 14.5 ng/mL; 33% on ADT	29% of patients N+/M+ on PSMA PET/CT; Detection of at least one PSMA− FDG+ lesion in 6%
CRPCa	46	Wang et al. [33] (trial group)	37	(i) Rising PSA ≤2 ng/ml; (ii) Testosterone <50 ng/dL; (iii) PSA doubling time ≤10 months; (iv) N0M0 on CT and bone scan	Median PSA: 0.57 ng/mL; 73% ISUP ≥4; 100% after RP; 19% postop EBRT	Subsequent addition of FDG after PSMA PET/CT increased detection of N+/M+ from 65% to 73%; Detection of at least one PSMA− FDG+ lesion in 24%
		Wang et al. [33] (retrospective)	9	(i) Not defined	Median PSA: 2.26 ng/mL; 89% ISUP ≥4	Detection of at least one PSMA− FDG+ lesion in 33%