68 Ga-FAPI PET/CT Detected Non-PSMA/FDG-Avid Primary Tumor in De Novo Metastatic Prostate Cancer.

68 Ga-labeled PET tracer targeting PSMA is a promising diagnostic approach for staging and restating of prostate cancer (PCa), but cases with clinically relevant PCa and false-negative PSMA PET/CT have been reported. In this case, we reported 68 Ga-PSMA, 18 F-FDG, and 68 Ga-FAPI PET/CT findings in a 65-year-old man with de novo metastatic PCa. 68 Ga-FAPI PET/CT detected non-PSMA/FDG-avid primary PCa, consisting with multiparametric MRI findings. The subsequent histopathologic examination confirmed a Gleason 4 + 5 PCa. This case highlighted that 68 Ga-FAPI PET/CT may be a useful imaging modality for primary PCa detection and localization.