Head-to-head comparison of [ 68 Ga]Ga-P16-093 and [ 68 Ga]Ga-PSMA-617 in dynamic PET/CT evaluation of the same group of recurrent prostate cancer patients

Purpose This study was prospectively designed to evaluate the early dynamic organ distribution and tumor detection capability of [ 68 Ga]Ga-P16-093, which was compared with [ 68 Ga]Ga-PSMA-617 in the same group of recurrent prostate cancer patients. Methods Twenty patients with recurrent prostate cancer were enrolled. In 2 consecutive days, each patient underwent a 60-min dynamic PET/CT scan after intravenous administration of 148–185 MBq (4–5 mCi) [ 68 Ga]Ga-P16-093 and [ 68 Ga]Ga-PSMA-617, respectively. Following a low-dose CT scan, serial dynamic PET scans were performed from head to proximal thigh at 9 time points (30 s/bed at 4, 7, 10, 13, and 16 min; 1 min/bed at 20, 30, and 45 min; and 2 min/bed at 60 min). Standardized uptake values were measured for semi-quantitative comparison. Results [ 68 Ga]Ga-P16-093 PET/CT revealed a significantly higher tumor uptake at 4 min (SUVmax 7.88 ± 5.26 vs. 6.01 ± 3.88, P < 0.001), less blood pool retention at 4 min (SUVmean 5.12 ± 1.16 vs. 6.14 ± 0.98, P < 0.001), and lower bladder accumulation at 60 min (SUVmean 31.33 ± 27.47 vs. 48.74 ± 34.01, P = 0.042) than [ 68 Ga]Ga-PSMA-617 scan. Significantly higher [ 68 Ga]Ga-P16-093 uptakes were also observed in the parotid gland, liver, spleen, and kidney. Besides, [ 68 Ga]Ga-P16-093 exhibited a better detectability of tumor than [ 68 Ga]Ga-PSMA-617 (366 vs. 321, P = 0.009). Conclusions [ 68 Ga]Ga-P16-093 showed advantages over [ 68 Ga]Ga-PSMA-617 with higher tumor uptakes, tumor-to-blood pool ratio and detection capability, less blood pool, and bladder accumulation in recurrent prostate cancer patients. Trial registration: [ 68 Ga]Ga-P16-093 and [ 68 Ga]Ga-PSMA-617 PET/CT Imaging in the Same Group of Prostate Cancer Patients (NCT04796467, Registered 12 March 2021, retrospectively registered) URL of registry: https://clinicaltrials.gov/ct2/show/NCT04796467