Intraindividual Comparison of 18 F-PSMA-1007 with Renally Excreted PSMA Ligands for PSMA PET Imaging in Patients with Relapsed Prostate Cancer

J Nucl Med. 2020 May;61(5):729-734. doi: 10.2967/jnumed.119.234898. Epub 2019 Oct 18.

Abstract

18F-prostate-specific membrane antigen (PSMA)-1007 is excreted mainly through the liver. We benchmarked the performance of 18F-PSMA-1007 against 3 renally excreted PSMA tracers. Methods: Among 668 patients, we selected 27 in whom PET/CT results obtained with 68Ga-PSMA-11, 18F-DCFPyL (2-(3-(1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentanedioic acid), or 18F-JK-PSMA-7 (JK, Juelich-Koeln) were interpreted as equivocal or negative or as oligometastatic disease (PET-1). Within 3 wk, a second PET scan with 18F-PSMA-1007 was performed (PET-2). The confidence in the interpretation of PSMA-positive locoregional findings was scored on a 5-point scale, first in routine diagnostics (reader 1) and then by an independent second evaluation (reader 2). Discordant PSMA-positive skeletal findings were examined by contrast-enhanced MRI. Results: For both readers, 18F-PSMA-1007 facilitated the interpretability of 27 locoregional lesions. In PET-2, the clinical readout led to a significantly lower number of equivocal locoregional lesions (P = 0.024), and reader 2 reported a significantly higher rate of suspected lesions that were falsely interpreted as probably benign in PET-1 (P = 0.023). Exclusively in PET-2, we observed a total of 15 PSMA-positive spots in the bone marrow of 6 patients (22%). None of the 15 discordant spots had a morphologic correlate on the corresponding CT scan or on the subsequent MRI scan. Thus, 18F-PSMA-1007 exhibits a significantly higher rate of unspecific medullary spots (P = 0.0006). Conclusion: 18F-PSMA-1007 may increase confidence in interpreting small locoregional lesions adjacent to the urinary tract but may decrease the interpretability of skeletal lesions.

Keywords: 18F-DCFPyL; 18F-JK-PSMA-7; 18F-PSMA-1007; 68Ga-PSMA-11; PET; PSMA tracer; prostate cancer.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Fluorine Radioisotopes*
  • Humans
  • Kidney / metabolism*
  • Ligands
  • Male
  • Middle Aged
  • Niacinamide / analogs & derivatives*
  • Niacinamide / pharmacokinetics
  • Oligopeptides / pharmacokinetics*
  • Positron Emission Tomography Computed Tomography*
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / metabolism*
  • Recurrence
  • Tissue Distribution
  • Whole Body Imaging

Substances

  • Fluorine Radioisotopes
  • Ligands
  • Oligopeptides
  • PSMA-1007
  • Niacinamide
  • Fluorine-18