Can (18)F-PSMA-7Q PET/CT replace prostate biopsy for the diagnosis of prostate cancer?—A single-center retrospective study

BACKGROUND: Of the currently available prostate-specific membrane antigen (PSMA) positron emission tomography (PET) tracers, although (68)Ga-PSMA-11 and (18)F-DCFPyL have been approved by the US Food and Drug Administration (FDA), both tracers are excreted rapidly through the urinary tract, resulting in strong accumulation in the bladder and blurring the prostate.(18)F-PSMA-7Q is a novel quinoline-containing PSMA PET tracer developed by our team, which is primarily excreted through the liver. It can reduce the incidence of urine-induced false-positives in the prostate. We aimed to explore the diagnostic efficacy of (18)F-PSMA-7Q PET/computed tomography (CT), and when (18)F-PSMA-7Q PET/CT can be used instead of prostate biopsy to diagnose prostate cancer. METHODS: Patients who underwent (18)F-PSMA-7Q PET/CT for prostate cancer staging or prostate biopsy guidance at our institution between July 2020 and December 2021 were retrospectively enrolled. Molecular imaging PSMA (miPSMA) scores were assigned for intra-prostatic lesions according to the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) criteria, and the diagnostic efficacy of (18)F-PSMA-7Q PET/CT for different miPSMA scores was evaluated using pathological diagnosis as the gold standard. RESULTS: Of the 125 enrolled patients, 101 had prostate cancer, and 24 had prostatic hyperplasia or prostatitis. miPSMA ≥2 was the optimal diagnostic threshold, and area under curve (AUC) was 0.948, the sensitivity and specificity were 91.1% and 83.0%. The prostate cancer detection rates of (18)F-PSMA-7Q PET/CT were 14.3% (3/21), 60.0% (6/10), 96.7% (58/60), and 100% (34/34) for patients with miPSMA scores of 0, 1, 2, and 3, respectively. There was no significant difference in the detection rate of prostate cancer between groups with miPSMA scores of 2 and 3, but there were significant differences between any other 2 groups. CONCLUSIONS: The prostate cancer detection rate of (18)F-PSMA-7Q PET/CT was high for lesions with greater miPSMA scores of 2 and 3. For patients with a high miPSMA score, particularly those with a miPSMA score of 3, prostate biopsy can be omitted and prostate cancer-related treatment can be considered.