DOI: 10.1007/s00259-018-4189-7Pages: 1-9

68Ga-PSMA-11 PET/CT in recurrent prostate cancer: efficacy in different clinical stages of PSA failure after radical therapy

1. University of Bologna, Metropolitan Nuclear Medicine of Bologna

2. University of California Los Angeles (UCLA), Ahmanson Translational Imaging Division, UCLA Nuclear Medicine, Department of Molecular and Medical Pharmacology

3. Policlinico S.Orsola-Malpighi, Azienda Ospedaliero-Universitaria di Bologna, Metropolitan Nuclear Medicine of Bologna

Correspondence to:
Francesco Ceci
Email: francesco.ceci3@unibo.it

Close

Abstract

Objectives

The primary objective was the evaluation of Gallium 68 (68Ga)-prostate-specific membrane antigen (PSMA)-11 positron emission tomography/computed tomography (PET/CT) detection rate, for identifying the site of prostate cancer (PCa) relapse (local vs systemic), stratifying the population according to different clinical stages of biochemical recurrence (BCR). Secondary aims were: 1) to evaluate the association of clinical/pathologic features and 68Ga-PSMA-11 PET/CT detection rate, 2) to compare 68Ga-PSMA-11 PET/CT with other imaging procedures, and 3) to evaluate the positive predictive value (PPV) in a per-patient analysis.

Material and methods

This population was enrolled through a prospective, open label, single-center trial performed at the Nuclear Medicine of the University Hospital of Bologna (Eudract: 2015-004589-27 OsSC). The inclusion criteria were: (1) proven PCa, (2) surgery or radiotherapy as definitive therapy, (3) proven BCR, (4) prostate-specific antigen (PSA) 0.2–2 ng/ml, (5) age ≥ 35 years, and 6() willing to sign an informed consent. Three-hundred and thirty-two (332) patients were enrolled between March 2016 and June 2017; mean/median PSA was 0.84/0.61 ng/ml, 97.9% (325/332) of patients received radical prostatectomy and 2.1% (7/332) radiotherapy. Different patterns of BCR were identified by referent physicians as follows: (a) persisting detectable PSA after radical prostatectomy in 13.5% (45/332) of patients (subgroup 1), (b) first-time PSA failure after radical therapy in 44.9% (149/332) (subgroup 2), and (c) PSA increase after salvage or hormonal therapy in 41.6% (138/332) (subgroup 3).

Results

Primary objective: 68Ga-PSMA-11 PET/CT detection rate was 53.6% (CI 95% 48.1%–59.1%). In a patient-based analysis, disease confined to pelvis (prostate bed and/or lymph-nodes) was detected in 24.7% of cases (82/332). The presence of at least one distant lesion was observed in 28.9% of cases (96/332). The detection rate in different subgroups was: subgroup 1 = 64.5%, subgroup 2 = 45.6%, and subgroup-3  = 58.7%. Secondary objectives: 1) PSA (p = 0.041) and PSAdt (p = 0.001) showed association with 68Ga-PSMA-11 PET/CT detection rate, and 2) correlative imaging was available in 73.2% of patients (243/332). When 68Ga-PSMA-11 PET/CT was positive, correlative imaging resulted negative in 83% of cases (108/130). 3) The calculated PPV was 96.2%.

Conclusion

Our data confirmed the efficacy of 68Ga-PSMA-11 PET/CT for detecting local vs systemic disease in PCa patients presenting PSA failure after radical therapy. Furthermore, 68Ga-PSMA-11 PET/CT detection rate is different depending on the clinical stage of BCR, and this information should be taken into consideration by referring physicians.

To access the full text, please Sign in

If you have institutional access, please click here

  • Accepted: Oct 3, 2018
  • Online: Oct 22, 2018

Article Tools

eanm
EJNMMI Ad