The value of 18 F-PSMA-1007 PET/CT in identifying non-metastatic high-risk prostate cancer.

Background: Clinical management decisions on prostate cancer (PCa) are often based on a determination of risk. ⁶⁸ Ga-prostate-specific membrane antigen (PSMA)-11-positron emission tomography (PET)/computer tomography (CT) is an attractive modality to assess biochemical recurrence of PCa, detect metastatic disease and stage of primary PCa, making it a promising strategy for risk stratification. However, due to some limitation of ⁶⁸ Ga-PSMA-11 the development of alternative tracers is of high interest. In this study, we aimed to investigate the value of ¹⁸ F-PSMA-1007 in identifying non-metastatic high-risk PCa.
Methods: A total of 101 patients with primary non-metastatic PCa who underwent ¹⁸ F-PSMA-1007 PET/CT were retrospectively analyzed. According to the European Association of Urology guidelines on PCa, patients were classified into intermediate-risk (IR) group or high-risk (HR) group. The maximum standardized uptake values (SUVmax) of the primary prostate tumor were measured on PET/CT images. The diagnostic performance of PET/CT for IR and HR PCa was calculated, and the relationship between the SUVmax of primary prostate tumor, prostate-specific antigen (PSA) level and Gleason score (GS) was analyzed.
Results: Of all 101 patients, 49 patients were classified into IR group and 52 patients were classified into HR group. There was a significant positive correlation between PSA level/GS and SUVmax (r = 0.561, r = 0.496, P < 0.001, respectively). Tumors with GS 6 and 7a showed significantly lower ¹⁸ F-PSMA-1007 uptake compared to patients with GS 8 and 9 (P < 0.01). SUVmax in patients of HR was significantly higher than those of IR (median SUVmax: 16.85 vs 7.80; P < 0.001). In receiver operating characteristic curve analysis, the optimal cutoff value of the SUVmax for identifying high-risk PCa was set as 9.05 (area under the curve: 0.829; sensitivity: 90.4%; specificity: 65.3%).
Conclusion: ¹⁸ F-PSMA-1007 PET/CT showed the powerful diagnosis efficacy for high-risk PCa, which can be used as an objective imaging reference index for clinical reference.