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

Abstract

The introduction of 18 F-labeled prostate-specific membrane antigen (PSMA)-targeted PET/CT tracers, first 18 F-DCFPyL (2-(3-{1-carboxy-5- [(6- 18 F-fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid) andmore recently 18 F-PSMA-1007 (((3S,10S,14S)-1-(4-(((S)-4-carboxy- 2-((S)-4-carboxy-2-(6- 18 F-fluoronicotinamido)butanamido)butanamido) methyl)phenyl)-3-(naphthalen-2-ylmethyl)-1,4,12-trioxo-2,5,11,13- tetraazahexadecane-10,14,16-tricarboxylic acid)), have demonstrated promising results for the diagnostic workup of prostate cancer. This clinical study presents an intraindividual comparison to evaluate tracer-specific characteristics of 18 F-DCFPyL versus 18 F-PSMA-1007. Methods: Twelve prostate cancer patients, drug-naïve or before surgery, received similar activities of about 250 MBq of 18 F-DCFPyL and 18 F-PSMA-1007 48 h apart and were imaged 2 h after injection on the same PET/CT scanner using the same reconstruction algorithm. Normal- organ biodistribution and tumor uptake were quantified using SUV max . Results: PSMA-positive lesions were detected in 12 of 12 prostate cancer patients. Both tracers, 18 F-DCFPyL and 18 F-PSMA- 1007, detected the same lesions. No statistical significance could be observed when comparing the SUV max of 18 F-DCFPyL and 18 F-PSMA- 1007 for local tumor, lymph node metastases, and bone metastases. With regard to normal organs, 18 F-DCFPyL had statistically significant higher uptake in kidneys, urinary bladder, and lacrimal gland. Vice versa, significantly higher uptake of 18 F-PSMA-1007 in muscle, submandibular and sublingual gland, spleen, pancreas, liver, and gallbladder was observed. Conclusion: Excellent imaging quality was achieved with both 18 F-DCFPyL and 18 F-PSMA-1007, resulting in identical clinical findings for the evaluated routine situations. Nonurinary excretion of 18 F-PSMA- 1007 might present some advantage with regard to delineation of local recurrence or pelvic lymph node metastasis in selected patients; the lower hepatic background might favor 18 F-DCFPyL in late stages, when rare cases of liver metastases can occur.