18F-flotufolastat (rhPSMA-7.3) PSMA-PET lowers bladder activity and lifts detection vs 18F-piflufolastat in low-PSA BCR

18F-piflufolastat (18F-DCFPyL; Pylarify) and 18F-flotufolastat (18F-rhPSMA-7.3; Posluma) are PSMA-targeted PET radiotracers for localizing recurrent prostate cancer; this prospective, multicentre, intra-patient comparator enrolled post-prostatectomy men with biochemical recurrence and PSA ≤0.5ng/mL (mean PSA 0.28ng/mL; n=55 evaluable), scanned ~60 minutes post-injection on the same scanner 1–10 days apart (NCT06604442). Median bladder SUVmean was higher with 18F-piflufolastat vs 18F-flotufolastat (29.0 vs 10.9; p<0.001), and majority-read patient-level detection was 27.3% (15/55) vs 45.5% (25/55), with region-level DRs of 10.9% vs 18.2% (prostate bed), 14.5% vs 16.4% (pelvic nodes), and 7.3% vs 21.8% (extra-pelvic). In this very-low-PSA setting, the 18F-piflufolastat detection rate here sits at/under published ranges for PSMA-PET at PSA 0.2–0.5ng/mL (often ~30–40% for 18F-DCFPyL), while rhPSMA-7.3 has been reported around ~60% in PSA 0.2–<0.5ng/mL cohorts—suggesting this head-to-head improvement is directionally consistent with prior literature, and plausibly driven in part by reduced urinary “noise” near the prostate bed.