Dynamic ¹⁸F-DCFPyL PET/CT imaging of biopsy-proven high-risk primary prostate cancer patients

Objectives: The aim of this study was to investigate the pharmacokinetics of ¹⁸F-DCFPyL, a ¹⁸F-labelled PSMA ligand, in benign and malignant primary prostate tissue of clinically high-risk patients through dynamic PET/CT imaging.

Methods: Pharmacokinetics were evaluated using a dynamic PET/CT scan of the pelvis for the first 45 minutes post-injection (p.i.) followed by a static PET/CT at 2 hours p.i. in primary prostate tumors of 10 biopsy-proven high-risk patients with ¹⁸F-DCFPyL. SUV values were used to plot and determine time activity curves, two-tissue compartmental modelling, and Patlak plots to compare uptake and kinetics between benign and cancerous prostate tissue.

Results: Uptake was statistically significantly greater in primary prostate tumors in comparison with that of BPH and normal prostate tissue at 5 minutes p.i., 30 minutes p.i., and 120 minutes p.i. (P = 0.0002) when examining both SUV_max and SUV_mean values. This two-tissue compartmental model found an overall influx value (K_i) of 0.063 in primary prostate cancer, demonstrating a K_i over 15-fold higher in malignant prostate tissue compared with BPH (K_i = 0.004) and normal prostate tissue (K_i = 0.005) (P = 0.0001).

Conclusions: Primary prostate cancer is readily identified on dynamic and static delayed ¹⁸F-DCFPyL PET images. The tumor-to-background ratio increases over time, with optimal ¹⁸F-DCFPyL PET/CT imaging at 120 minutes p.i. for evaluation of prostate cancer. Primary prostate cancer demonstrates different uptake kinetics in comparison to BPH and normal prostate tissue. ¹⁸F-DCFPyL PET/CT imaging is highly promising in detection of prostate cancer and has great clinical potential. Keywords: ¹⁸F-DCFPyL Dynamic PET/CT, primary prostate cancer, two-tissue compartmental model