⁶⁸Ga-PSMA-11 PET/CT for Detecting Biochemical Recurrence after Radical Prostatectomy in a Racially Diverse Population...

Prostate cancer (PCa) is the second most diagnosed cancer in men, with Black and African American men (BAAM) experiencing higher incidence, more aggressive disease, and greater risk of biochemical recurrence (BCR) following radical prostatectomy (RP). This study investigated the use of ⁶⁸Ga-PSMA-11 PET/CT to explore BCR patterns between racial groups at low prostate-specific antigen (PSA) levels (≤ 2.0 ng/mL) post-RP.

This retrospective study included 49 men with BCR post-RP: 17 BAAM and 32 White American men (WAM) who underwent ⁶⁸Ga-PSMA-11 PET/CT at a National Cancer Institute-designated comprehensive cancer center between 2017 and 2021. Clinical and pathological data, including baseline PSA, PSA density, and PSA at scan, along with ⁶⁸Ga-PSMA-11 PET/CT-derived parameters (detection rate, standardized uptake values [SUVmax and SUVmean], PSMA tumor volume [PSMA-TV], and total lesion PSMA [TL-PSMA]), were collected and compared between groups.

The overall detection rate was 57% (28/49), with 47% (8/17) in BAAM and 63% (20/32) in WAM (p = 0.39). BAAM had significantly higher baseline PSA levels (median: 13.80 versus 7.22 ng/mL; p < 0.001) and PSA density (0.59 versus 0.16 ng/mL²;p < 0.001). At recurrence, PSA levels and lesion distribution were statistically similar. While WAM exhibited slightly higher SUVmax and SUVmean, BAAM demonstrated higher PSMA-TV, TL-PSMA, and whole-body volumetrics (wbPSMA-TV and wbTL-PSMA); although the differences were not statistically significant, they highlight areas for future exploration.

Despite BAAM presenting with more aggressive features at primary diagnosis, BAAM and WAM exhibited comparable PSMA-PET-derived tumor burden at recurrence. These findings will inform future studies with large, racially diverse populations.