Standardised uptake values as determined on prostate‐specific membrane antigen positron emission tomography/computed tomography is associated with oncological outcomes in patients with prostate cancer

OBJECTIVES: To investigate the association between intraprostatic, intratumoral maximum standardised uptake values (SUV(max)) on prostate‐specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) in patients with prostate cancer (PCa) prior to robot‐assisted radical prostatectomy (RARP) and pathology outcomes, including pathological International Society of Urological Pathology score (pISUP) and lymph node (LN) status (pN0/pN1). PATIENTS AND METHODS: A bi‐centric, secondary analysis of two previous, prospective cohort studies was performed in 318 patients with biopsy confirmed PCa and who were scheduled for RARP. Before surgery, patients received a PSMA PET/CT with either (68)Ga‐PSMA‐11 (59% of the patients) or (18)F‐PSMA (DCFPyL; 41%) as radiotracer. PET/CT images were analysed both visually and semi‐quantitatively by measuring the SUV(max) of the most intense suspect lesion in the prostate. The association between the SUV(max) of the primary tumour and pre‐ and postoperative variables was analysed. RESULTS: The SUV(max) was associated with clinical and biopsy preoperative variables, as well as with pISUP score and pathological tumour stage. Patients with a pISUP of ≤2 showed significantly lower SUV(max) compared to patients with a pISUP of >2 for both tracers (SUV(max) (18)F‐PSMA: median 5.1 vs 9.6, P = 0.002; SUV(max) (68)Ga‐PSMA‐11: 6.6 vs 8.6, P = 0.003). Moreover, patients with pN1 had significantly higher median SUV(max) than those with pN0/pNx for both tracers (SUV(max) (18)F‐PSMA: 7.9 vs 12.3, P = 0.04; SUV(max) (68)Ga‐PSMA‐11: 7.6 vs 12.0, P < 0.001). On multivariable logistic regression analysis, the intraprostatic SUV(max) was an independent predictor of pN1 for both (68)Ga‐PSMA‐11 (per doubling: odds ratio [OR] 1.96, 95% confidence interval [CI] 1.27–3.01)) and (18)F‐PSMA (per doubling: OR 1.79, 95% CI 1.06–3.03). CONCLUSION: Intraprostatic, intratumoral PSMA intensity on PET/CT, as semi‐quantitatively expressed by SUV(max), may be a valuable innovative biomarker in patients with localised PCa, as it is highly associated with known conventional prognostic factors, such as pISUP and LN status.