[18F]PSMA-1007 PET/CT in biochemical recurrence after radical prostatectomy: A single-center experience of detection rate and lesion distribution

Abstract

Objective To define the diagnostic yield and anatomical distribution of [18F]prostate-specific membrane antigen (PSMA)-1007 positron emission tomography/computed tomography (PET/CT) in post-radical-prostatectomy biochemical recurrence (BCR) and to establish prostate-specific antigen (PSA)-stratified performance benchmarks, independent predictors of PET positivity, and clinical utility for PSMA-guided metastasis-directed therapy. Methods A single-centre retrospective cohort of 245 consecutive BCR patients (PSA ≥ 0.2 ng/ mL) who underwent uniform [18F]PSMA-1007 PET/CT (90 ± 10 min post-injection; molar activity > 30 GBq µmol-1) between June 2022 and November 2025 was anal-ysed. Detection rates were correlated with PSA strata, and independent predictors of PET positivity were identified via multivariable logistic regression. Lesion location was verified by histology, targeted therapy response, or unequivocal imaging follow-up. Inter-observer agreement for image interpretation was quantified using Cohen’s kappa, Results At median PSA 0.9 ng/mL (interquartile range 0.5–2.1), 184/245 patients (75.1%, 95% CI: 69.3–80.3%) exhibited ≥ 1 [18F]PSMA-1007-avid lesion. Detection rates increased with PSA: 56.5% (0.2–0.5 ng/mL) to 90.5% (≥ 1.5 ng/mL). Independent predictors of PET positivity were serum PSA (OR = 2.87), ISUP grade (OR = 1.63), and PSA doubling time (OR = 0.72) (all P < 0.01). In 132 verified cases, a “pelvic-first” pattern was observed: isolated prostatic fossa (34.8%), isolated nodal (38.6%), isolated osseous (20.4%), and multi-region disease (6.1%). Median SUVmax was comparable across lesion types (≈ 17.5; P = 0.63), with excellent inter-observer agreement (Cohen’s κ = 0.86 for positivity, 0.82 for localization; both P < 0.001). Conclusion [18F]PSMA-1007 PET/CT delivers high, PSA-dependent detection efficiency even at PSA < 0.5 ng/mL, with excellent inter-observer reliability. Serum PSA, ISUP grade, and PSA doubling time independently predict PET positivity, and the modality accurately maps predominantly pelvic, oligometastatic recurrences suitable for focal salvage therapy. These data support its utility as a first-line imaging tool for post-prostatectomy BCR staging.