68Ga-PSMA-11 PET/CT in recurrent hormone-sensitive prostate cancer (HSPC): a prospective single-centre study in patients eligible for salvage therapy.

The primary objective is to assess the efficacy of 68Ga-PSMA-11-PET/CT to detect recurrent location(s) in hormone-sensitive prostate cancer (PCa). Secondary objectives are (1) to evaluate changes in clinical management; (2) to determine which covariates independently predict positive scan; (3) to assess 68Ga-PSMA-11-PET/CT performance in different settings of PSA relapse.

Inclusion criteria include (1) histologically diagnosed PCa; (2) previous radical therapy; (3) proven biochemical recurrence (BCR) or biochemical persistence (BCP); (4) hormone-sensitive PCa (HSPC); (5) androgen deprivation therapy (ADT)-free for at least 6 months; (6) PSA < 1.5 ng/mL or any PSA in case of negative choline-PET/CT (n = 38). Changes in clinical management were defined by multidisciplinary tumour-board. Clinical settings were BCP (group-1, n = 25); first-time BCR (group-2, n = 121); BCR after salvage therapy (group-3, n = 77).

Two hundred twenty-three (223) consecutive patients were enrolled: median PSA = 0.65 ng/mL (0.2-8.9) and median PSAdt = 9.3 months (0.4-144.6). 96.9% received RP as primary therapy. 68Ga-PSMA-11-PET/CT positivity rate was 39.9% (CI95% 33.5-46.7%). Disease confined to pelvis was detected in 23.3% of cases. At least one distant lesion was observed in 16.6% of cases. Secondary objectives are as follows: (1) changes in clinical management were observed in 34.5% of patients; (2) PSA, PSAdt and T stage > 3a were independent predictors (all p < 0.03); (3) 68Ga-PSMA-11-PET/CT positivity rate was 56% (in group 1, 36.3% in group 2, 40.3% in group 3.

This study attested the overall good performance of 68Ga-PSMA-11-PET/CT to detect PCa locations in HSPC patients eligible for salvage therapy, influencing the therapy management in 35.4% of cases. Furthermore, patient characteristics are influencing factors of 68Ga-PSMA-11-PET/CT positivity rate and should be considered to reduce false negative scan.

European journal of nuclear medicine and molecular imaging. 2020 Apr 20 [Epub ahead of print]

Désirée Deandreis, Alessia Guarneri, Francesco Ceci, Beatrice Lillaz, Sara Bartoncini, Marco Oderda, Daniele Giovanni Nicolotti, Emanuela Pilati, Roberto Passera, Andrea Zitella, Marilena Bellò, Ramona Parise, Roberta Carlevato, Umberto Ricardi, Paolo Gontero

Nuclear Medicine, Department of Medical Sciences, AOU Città della Salute e della Scienza di Torino, University of Turin, Corso AM Dogliotti, 14, 10126, Turin, Italy., Radiation Oncology, Department of Oncology, AOU Città della Salute e della Scienza di Torino, Turin, Italy., Nuclear Medicine, Department of Medical Sciences, AOU Città della Salute e della Scienza di Torino, University of Turin, Corso AM Dogliotti, 14, 10126, Turin, Italy. ., Urology, Department of Surgical Sciences, AOU Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy.