Intra-individual comparison of ¹⁸F-PSMA-1007 and ¹⁸F-DCFPyL PET/CT in the prospective evaluation of patients with newly diagnosed prostate carcinoma: A pilot study

Abstract

Introduction: The introduction of ¹⁸F-labelled prostate-specific membrane antigen (PSMA) targeted positron emission tomography/computed-tomography (PET/CT) tracers, firstly ¹⁸F-DCFPyL and more recently ¹⁸F-PSMA-1007, have demonstrated promising results for the diagnostic workup of prostate cancer (PCa). This clinical study presents an intra-individual comparison to evaluate tracer-specific characteristics of ¹⁸F-DCFPyL versus ¹⁸F-PSMA-1007. Methods: Twelve prostate cancer patients, drug naive or prior to surgery, received similar activities of about 250 MBq ¹⁸F-DCFPyL and ¹⁸F-PSMA-1007 48 h apart and were imaged 2 h p.i. in the same PET/CT-scanner using the same reconstruction-algorithm. Normal organ biodistribution and tumor uptakes were quantified using SUV_max. Results: PSMA-positive lesions were detected in twelve out of twelve PCa patients. Both tracers, ¹⁸F-DCFPyL and ¹⁸F-PSMA-1007, detected the identical lesions. No statistical significance could be observed when comparing the SUV_max of ¹⁸F-DCFPyL and ¹⁸F-PSMA-1007 for local tumor, lymph node metastases and bone metastases. With regard to normal organs, ¹⁸F-DCFPyL presented statistically significant higher uptake in kidneys, urinary bladder and lacrimal gland. Vice versa, significantly higher uptake of ¹⁸F-PSMA-1007 in muscle, submandibular and sublingual gland, spleen, pancreas, liver and gallbladder was observed. Conclusion: Excellent imaging quality was achieved with both ¹⁸F-DCFPyL and ¹⁸F-PSMA-1007 resulting in identical clinical findings for the evaluated routine situations. Non-urinary excretion of ¹⁸F-PSMA-1007 might present some advantage with regard to delineation of local recurrence or pelvic lymph-node metastasis in selective patients; the lower hepatic background might favor ¹⁸F-DCFPyL in very late stages when rare cases of liver metastases can occur.