Head-to-head comparison of [${}^{68}$Ga]Ga-P16-093 and 2-[${}^{18}$F]FDG PET/CT in patients with clear cell renal cell carcinoma. A pilot study

This pilot study was prospectively designed to evaluate and compare the diagnostic value of PET/CT using a PSMA-specific tracer [${}^{68}$Ga]Ga-P16-093 and a glucose metabolism probe 2-[${}^{18}$F]FDG in clear cell renal cell carcinoma (ccRCC) patients. Forty-two pathologically confirmed ccRCC patients were included. Within 1 week, each patient underwent [${}^{68}$Ga]Ga-P16-093 and 2-[${}^{18}$F]FDG PET/CT. In addition to visual analysis of tumor number, the standardized uptake value (SUV) was measured for semiquantitative comparison and correlation analysis. For primary ccRCC patients, [${}^{68}$Ga]Ga-P16-093 PET/CT demonstrated a significantly higher detection rate (19/22 vs. 13/22, P = 0.031) and higher tumor uptake (15.7 ± 9.0 vs. 5.1 ± 3.4, P < 0.001) than 2-[${}^{18}$F]FDG PET/CT. In addition, the SUVmax of the primary tumor on [${}^{68}$Ga]Ga-P16-093 and 2-[${}^{18}$F]FDG PET/CT was significantly correlated with pT stage (for [${}^{68}$Ga]Ga-P16-093, r = 0.550, P = 0.008; for 2-[${}^{18}$F]FDG, r = 0.514, P = 0.014) and WHO/ISUP grade (for [${}^{68}$Ga]Ga-P16-093, r = 0.566, P = 0.006; for 2-[${}^{18}$F]FDG, r = 0.492, P = 0.020), respectively. For metastatic ccRCC patients, [${}^{68}$Ga]Ga-P16-093 PET/CT also demonstrated a better detection rate (21/22 vs. 14/22, P = 0.008) and higher tumor uptake (11.0 ± 6.4 vs. 4.4 ± 2.7, P < 0.001) than 2-[${}^{18}$F]FDG PET/CT. The SUVmax on [${}^{68}$Ga]Ga-P16-093 PET/CT had a significant association with PSMA expression in primary ccRCC (r = 0.776, P < 0.001) and metastatic ccRCC (r = 0.626, P = 0.029). [${}^{68}$Ga]Ga-P16-093 PET/CT demonstrates significantly better tumor detectability than 2-[${}^{18}$F]FDG PET/CT for ccRCC patients.