Impact of intraprostatic PSMA maximum standardised uptake value following prostatectomy: a systematic review and meta-analysis.

Objective: To perform a systematic review and meta-analysis to assess the relationship between intraprostatic maximum standardised uptake value (SUV) of the dominant prostatic lesion as measured on preoperative prostate-specific membrane antigen (PSMA) positron emission tomography (PET) with radical prostatectomy International Society of Urological Pathology (ISUP) Grade Group, pathological tumour (pT) staging, and biochemical recurrence (BCR).

Methods: Prostate-specific membrane antigen PET may offer non-invasive assessment of histopathological and oncological outcomes before definitive treatment. SUV of the dominant lesion has been explored as a prognostic biomarker. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we performed reviews of digital libraries and databases and retrieved studies reporting SUV quantified on PSMA PET computed tomography or magnetic resonance imaging and subsequent radical prostatectomy ISUP Grade Group, pT stage, and BCR. Quality assessment was performed using Quality Assessment of Diagnostic Accuracy Studies-2 and Prediction model Risk of Bias Assessment tools. Random effects meta-analysis and meta-regression by ISUP Grade Group and pT2 vs pT3/4 stage was performed. This study was registered on the International Prospective Register of Systematic Reviews (PROSPERO: CRD42023408170).

Evidence Synthesis: After removing duplicates, 23 studies were included for review. Pooled SUV (95% confidence interval [CI]) increased monotonically with advancing ISUP Grade Group, with ISUP 1: 5.8 (95% CI 3.9-7.7), through to ISUP 5: 17.3 (95% CI 13.1-21.5). For pT2 disease, pooled SUV: 9.7 (95% CI 7.8-11.5) increasing to 13.8 (95% CI 10.9-16.7) for pT3/4 disease. Substantial inconsistency was noted (I >50%) for all subgroups. This was not attenuated by restricting analysis only to studies using [Ga]Ga-PSMA-11. Narrative synthesis of six papers reporting BCR showed increasing SUV was associated with reduced time to BCR.

Conclusion: Preoperative intraprostatic PSMA SUV increases monotonically with higher ISUP Grade Group and pathological tumour stage. Higher SUV is associated with reduced BCR-free survival. However, the use of single SUV thresholds for clinical decision making is not recommended as variability between studies is high.