A comparison of ¹⁸F-DCFPyL, ¹⁸F-NaF and ¹⁸F-FDG PET/CT in a prospective cohort of men with metastatic prostate cancer

Abstract

Introduction: ¹⁸F-DCFPyL, ¹⁸F-NaF and ¹⁸F-FDG PET/CT were compared in a prospective cohort of men with metastatic prostate cancer (PCa). Materials and Methods: 67 men (Group 1) with documented metastatic PCa underwent ¹⁸F-DCFPyL and ¹⁸F-NaF PET/CT and a subgroup of 30 men (Group 2) underwent additional imaging with ¹⁸F-FDG PET/CT. The tracers were compared for their detection rates, imaging concordance, associations with Prostate Specific Antigen (PSA), treatment at the time of imaging and castration status. Results: Overall, 61 men had metastatic disease detected on one or more scans, while 6 men were negative. In Group 1, ¹⁸F-NaF detected significantly more metastatic lesions than ¹⁸F-DCFPyL (median of 3 lesions versus 2, P = 0.001) even after eliminating benign causes of ¹⁸F-NaF uptake. This difference was particularly clear for men receiving treatment (P = 0.005) or who were castrate resistant (P = 0.014). The median percentage of bone lesions that were concordant on ¹⁸F-DCFPyL and ¹⁸F-NaF was 50%. In Group 2, ¹⁸F-DCFPyL detected more lesions than ¹⁸F-FDG (median of 5 lesions versus 2, P = 0.0003), regardless of PSA level, castration status or treatment. The median percentage of lesions that were concordant on ¹⁸F-DCFPyL and ¹⁸F-FDG was 22.2%. This percentage was slightly higher for castrate-resistant than castrate-sensitive men (P = 0.048). Conclusion: ¹⁸F-DCFPyL PET/CT is the most versatile of the three PET agents for metastatic PCa however, ¹⁸F-NaF detects more bone metastases. Imaging reveals substantial tumor heterogeneity with only 50% concordance between ¹⁸F-DCFPyL and ¹⁸F-NaF and 22% concordance for ¹⁸F-DCFPyL and ¹⁸F-FDG. This indicates considerable phenotypic differences among metastatic lesions.