18F-fluciclovine PET-CT and 68Ga-PSMA-11 PET-CT in patients with early biochemical recurrence after prostatectomy: a prospective, single-centre, single-arm, comparative imaging trial.

National Comprehensive Cancer Network guidelines consider 18F-fluciclovine PET-CT for prostate cancer biochemical recurrence localisation after radical prostatectomy, whereas European Association of Urology guidelines recommend prostate-specific membrane antigen (PSMA) PET-CT. To the best of our knowledge, no prospective head-to-head comparison between these tests has been done so far. The aim of this study was to compare prospectively paired 18F-fluciclovine and PSMA PET-CT scans for localising biochemical recurrence of prostate cancer after radical prostatectomy in patients with low prostate-specific antigen (PSA) concentrations (<2·0 ng/mL).

This was a prospective, single-centre, open-label, single-arm comparative study done at University of California Los Angeles (Los Angeles, CA, USA). Patients older than 18 years of age with prostate cancer biochemical recurrence after radical prostatectomy and PSA levels ranging from 0·2 to 2·0 ng/mL without any prior salvage therapy and with a Karnofsky performance status of at least 50 were eligible. Patients underwent 18F-fluciclovine (reference test) and PSMA (index test) PET-CT scans within 15 days. Detection rate of biochemical recurrence at the patient level and by anatomical region was the primary endpoint. A statistical power analysis demonstrated that a sample size of 50 patients was needed to show a 22% difference in detection rates in favour of PSMA (test for superiority). Each PET scan was interpreted by three independent masked readers and a consensus majority interpretation was generated (two vs one) to determine positive findings. This study is registered with ClinicalTrials.gov, number NCT02940262, and is complete.

Between Feb 26, 2018, and Sept 20, 2018, 143 patients were screened for eligibility, of whom 50 patients were enrolled into the study. Median follow-up was 8 months (IQR 7-9). The primary endpoint was met; detection rates were significantly lower with 18F-fluciclovine PET-CT (13 [26%; 95% CI 15-40] of 50) than with PSMA PET-CT (28 [56%; 41-70] of 50), with an odds ratio (OR) of 4·8 (95% CI 1·6-19·2; p=0·0026) at the patient level; in the subanalysis of the pelvic nodes region (four [8%; 2-19] with 18F-fluciclovine vs 15 [30%; 18-45] with PSMA PET-CT; OR 12·0 [1·8-513·0], p=0·0034); and in the subanalysis of any extrapelvic lesions (none [0%; 0-6] vs eight [16%; 7-29]; OR non-estimable [95% CI non-estimable], p=0·0078).

With higher detection rates, PSMA should be the PET tracer of choice when PET-CT imaging is considered for subsequent treatment management decisions in patients with prostate cancer and biochemical recurrence after radical prostatectomy and low PSA concentrations (≤2·0 ng/mL). Further research is needed to investigate whether higher detection rates translate into improved oncological outcomes.

None.

The Lancet. Oncology. 2019 Jul 30 [Epub]

Jeremie Calais, Francesco Ceci, Matthias Eiber, Thomas A Hope, Michael S Hofman, Christoph Rischpler, Tore Bach-Gansmo, Cristina Nanni, Bital Savir-Baruch, David Elashoff, Tristan Grogan, Magnus Dahlbom, Roger Slavik, Jeannine Gartmann, Kathleen Nguyen, Vincent Lok, Hossein Jadvar, Amar U Kishan, Matthew B Rettig, Robert E Reiter, Wolfgang P Fendler, Johannes Czernin

Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Institute of Urologic Oncology, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA. Electronic address: ., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Nuclear Medicine, Department of Medical Sciences, University of Turin, Turin, Italy., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Technical University of Munich, School of Medicine, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich, Germany., Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA., Molecular Imaging and Nuclear Medicine Therapeutics, Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia., Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany., Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway., Metropolitan Nuclear Medicine, S Orsola-Malpighi University Hospital, Bologna, Italy., Division of Nuclear Medicine, Department of Radiology, Loyola University Medical Center, Maywood, IL, USA., Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA; Department of Medicine Statistics Core, University of California Los Angeles, Los Angeles, CA, USA., Department of Medicine Statistics Core, University of California Los Angeles, Los Angeles, CA, USA., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA., Division of Nuclear Medicine, Department of Radiology, University of Southern California, Los Angeles, CA, USA., Institute of Urologic Oncology, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA; Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA, USA., Institute of Urologic Oncology, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA; Department of Urology, University of California Los Angeles, Los Angeles, CA, USA., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany., Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA; Institute of Urologic Oncology, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center, University of California Los Angeles, Los Angeles, CA, USA.