18F-PSMA-1007 PET/MR for Early Detection of Biochemical Recurrence of Prostate Cancer in Very Low (≤ 0.5 ng/mL) Prostate-Specific Antigen Levels

Abstract Purpose To evaluate the diagnostic efficacy of 18F-PSMA-1007 PET/MR (PSMA-PET) in detecting biochemical recurrence (BCR) of prostate cancer (PCa) at very low (≤ 0.5 ng/mL) prostate-specific antigen (PSA) levels. Methods We recruited 157 PCa patients with BCR post-radical prostatectomy or radiation therapy between May 2021 and January 2023. Among them, 52 patients with PSA ≤ 0.5 ng/mL underwent PSMA-PET imaging. The imaging protocol included multiparametric MRI (mpMRI) and PET data analysis, with lesion classification based on PSMA-RADS version 1.0. Results The PSMA-PET imaging demonstrated a 63.5% detection rate for recurrent PCa in patients with low PSA levels. PSMA-PET detected 34 local recurrent lesions, 12 metastatic lymph nodes, and 4 skeletal metastases. Follow-up imaging reclassified initially equivocal lesions, increasing the detection rate to 73.1%. Outcomes from PSMA-PET imaging significantly influenced personalized treatment strategies, impacting clinical decisions for 17% of the participants in our investigation. Conclusion PSMA-PET significantly enhances the detection of recurrent PCa at low PSA levels, providing precise localization and aiding in personalized treatment strategies. Further research is essential to optimize its clinical application and validate long-term efficacy.