68Ga-PSMA PET/CT tumour intensity pre-operatively predicts adverse pathological outcomes and progression-free survival in localised prostate cancer.

Prostate-specific membrane antigen (PSMA) positron emission tomography (PSMA-PET) improves prostate cancer staging. Intraprostatic PSMA intensity may predict clinically relevant oncological outcomes. The aim of this study was to investigate the relationship between intraprostatic PSMA intensity and adverse pathology outcomes, including biochemical progression-free survival (PFS) after radical prostatectomy.

This is a cohort study of 71 patients with MRI-guided, biopsy-proven prostate cancer and pre-operative 68Ga-PSMA-11 PET/CT prior to radical prostatectomy (RP). Intraprostatic PSMA intensity was correlated to adverse pathology outcomes (Gleason score and upgrading from biopsy, pathological stage) and PFS using multivariate statistical analysis.

68Ga-PSMA-11 PET/CT intensity in vivo predicted all of Gleason score on RP, upgrading from biopsy to RP histopathology, pathological stage, positive surgical margins and PFS. 74.6% (53/71) of patients were free from progression at a median follow-up of 19.5 months (0.4-48 months). Predictive accuracy was particularly enhanced by PSMA among patients with biopsy Gleason score ≤ 3 + 4 (n = 39) as the most significant predictor of PFS according to Cox-proportional hazards regression. Cox-regression adjusted survival analysis predicted a 5.48-fold increase in hazard for Gleason score ≤ 3 + 4 patients with high (SUVmax > 8) compared with low (SUVmax < 8) PSMA intensity.

Intraprostatic 68Ga-PSMA-11 intensity is prognostic and may be a valuable new biomarker in localised prostate cancer, especially in men with biopsy-proven Gleason 3 + 4 disease considering an initial approach of active surveillance or focal therapy.

European journal of nuclear medicine and molecular imaging. 2020 Jul 22 [Epub ahead of print]

Matthew J Roberts, Andrew Morton, Peter Donato, Samuel Kyle, David A Pattison, Paul Thomas, Geoff Coughlin, Rachel Esler, Nigel Dunglison, Robert A Gardiner, Suhail A Doi, Louise Emmett, John Yaxley

Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia. ., Faculty of Medicine, The University of Queensland, Brisbane, 4006, Australia., Department of Urology, Royal Brisbane and Women's Hospital, Brisbane, Australia., Department of Population Medicine, College of Medicine, QU Health, Qatar University, Doha, Qatar., Department of Theranostics and Nuclear Medicine, St Vincent's Hospital, Sydney, Australia.