The novel prostate-specific membrane antigen (PSMA) tracer 18F-PSMA-1007 for positron emission tomography/computer tomography (PET/CT) imaging applications showed strong diagnostic efficacy for high-risk prostate cancer.
PSMA is a membrane-bound enzyme that is highly expressed in in prostate cancer cells. Targeted imaging of PSMA has recently been adapted into clinical settings, as expression levels are associated with prostate cancer progression. PSMA-based PET/CT imaging has been reported to enable better tumor detection compared with standard radiologic imaging.
This retrospective study assessed the clinical value of the novel tracer in diagnosing non-metastatic high-risk prostate cancer, enrolling 101 patients with primary non-metastatic disease who underwent imaging with 18F-PSMA-1007. Patients were divided into an Intermediate-risk (IR) group (n=49) or a high-risk (HR) group (n=52), according to European Association of Urology guidelines.
Maximum standardized uptake levels (SUVmax) of the primary prostate tumor were measured via PET/CT images. Diagnostic performance of the images for each group was calculated, and the relationship between the SUVmax of the primary tumor, prostate-specific antigen (PSA) level, and Gleason prostate cancer staging score (GS) was analyzed.
PSA level, GS, and SUVmax were significantly positively correlated (P < 0.001). The median SUVmax in patients of HR was significantly higher than those of IR (16.85 vs 7.80, respectively; P < 0.001).
The researchers found a positive correlation between the intensity of 18F-PSMA-1007 accumulation and the GS/PSA level in the primary prostate tumors. Tumors with GS 6 and 7a showed significantly lower 18F-PSMA-1007 uptake compared to tumors with GS 8 and 9 (P < 0.01).
“18F-PSMA-1007 was a great potential tracer for [prostate cancer (PCa)] PET/CT imaging,” the researchers concluded. “Furthermore, 18F-PSMA-1007 PET/CT showed powerful diagnostic performance for risk stratification of primary PCa, which can be used as a reference index for identifying high-risk PCa.”
The results of this study were published in EJNMMI Research.