Correlation of intraprostatic lesional SUVmax during PSMA PET/CT and adverse pathology at radical prostatectomy

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is a novel staging modality for prostate cancer (PCa) patients with a high positive predictive value for lesions within and outside of the prostate. To assess the ability of the maximum standardized uptake value (SUVmax) at PSMA PET/CT to predict adverse pathology at radical prostatectomy (RP).

Within a high-volume center database, we identified intermediate and high-risk PCa patients who had a PSMA PET/CT with an available intraprostatic SUVmax before RP between 2016 and 2021. Logistic regression modeling was used to test for the ability of SUVmax to predict non-organ confined disease or adverse pathology (non-organ confined and/or Gleason grade group ≥3) during RP. Kaplan-Meier analyses were used to compare biochemical recurrence (BCR)-free survival after RP stratified according to SUVmax.

Overall, 544 patients were identified. Of those, median lesional intraprostatic SUVmax was 9.5 at PSMA PET/CT. Median PSA was 8.1 ng/ml prior to RP. 50.7% vs. 49.3% had D'Amico intermediate and high-risk characteristics. Median follow-up was 24.6 months. BCR-free survival at 48 months after RP was 72.1% vs. 62.2% (p = 0.03) for patients with SUVmax <9.5 vs. SUVmax ≥9.5 at PSMA PET. In logistic regression models, SUVmax (continuously coded and stratified in <9.5 vs. ≥9.5) represented an independent predictor for non-organ confined disease and adverse pathology.

SUVmax ≥9.5 at PSMA PET/CT is an independent predictor of adverse pathology at RP. Moreover, it is associated with worse BCR-free survival after RP.