PET-CT With 18F-Fluciclovine and 68Ga-PSMA-11 in Patients With Early Biochemical Recurrence After Prostatectomy

[Balsam01]

TAKE-HOME MESSAGE

•This prospective, single-center trial evaluated 18F-fluciclovine PET/CT and 68Ga-PSMA-11 PET/CT for patients with early biochemical recurrence after prostatectomy. Detection rates were higher with PSMA PET/CT (56% vs 26%).

•The study authors concluded that, based on higher detection rates, PSMA is the preferable PET tracer for patients with prostate cancer and biochemical recurrence following radical prostatectomy.

– Neil Majithia, MD

BACKGROUND

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).

METHODS

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.

FINDINGS

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).

INTERPRETATION

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.

The Lancet Oncology

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

Lancet Oncol 2019 Jul 30;[EPub Ahead of Print], J Calais, F Ceci, M Eiber, TA Hope, MS Hofman, C Rischpler, T Bach-Gansmo, C Nanni, B Savir-Baruch, D Elashoff, T Grogan, M Dahlbom, R Slavik, J Gartmann, K Nguyen, V Lok, H Jadvar, AU Kishan, MB Rettig, RE Reiter, WP Fendler, J Czernin

[Christopherg]

I have had 3 reaccurances PLUS RP and radiation

Any idea which scan I should do now

I have doubling psa every 6 weeks

Thank you

Chris

[tallguy2]

Thanks for posting this.