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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.