PSMA-PET Imaging Linked to Earlier Advanced Therapies in Prostate Cancer

A new study has found that prostate-specific membrane antigen positron emission tomography (PSMA-PET) imaging is associated with earlier initiation of advanced therapies for prostate cancer compared to conventional bone scans. Among 5,893 patients newly diagnosed with prostate cancer between July 2021 and December 2023, 35.4% underwent PSMA-PET imaging, and its use increased significantly during the study period.

Patients who received PSMA-PET were more likely to start androgen receptor pathway inhibitor (ARPI) therapy (15.6%) compared to those who had bone scans (7.7%). PSMA-PET imaging was also associated with higher use of systemic therapies and radiotherapy for metastatic sites, while fewer patients underwent radical prostatectomy. The findings suggest that PSMA-PET imaging may identify more advanced disease, influencing treatment decisions.

Conventional imaging approaches — including computed tomography (CT) scans, bone scans, and magnetic resonance imaging (MRI) — have notable limitations in sensitivity, particularly in detecting low-volume disease. Over the past two decades, numerous phase 3 clinical trials evaluating therapies across multiple mechanisms of action have relied on these conventional techniques, which formed the foundation for clinical trial endpoints, regulatory approvals, and guideline development across the FDA, EMA, and international regulatory bodies. Clinicians increasingly recognized that these tools often failed to identify disease in patients with rising prostate-specific antigen (PSA) levels, especially in those with biochemical recurrence or non-metastatic castration-resistant prostate cancer.

In a separate real-world analysis of the therapeutic agent lutetium-177-PSMA-617, data on the first 50 patients with metastatic castration-resistant prostate cancer (mCRPC) treated at a single center in Quebec, Canada, were retrospectively analyzed. Patients received 7.4 GBq of lutetium-177-PSMA-617 every six weeks for up to six cycles. Median patient age was 72.55 years, and median pre-treatment PSA was 49.19 ng/mL. Overall, 26.0% of patients completed six cycles. Declines in PSA of 25%, 50%, and 90% were reached in 57%, 51%, and 17% of patients, respectively. After a mean follow-up of 8.5 months, 61% of patients not on ongoing therapy were alive, with an estimated median overall survival of 13.0 months. The researchers noted that real-world data show use of lutetium-177-PSMA-617 is feasible in a universal healthcare system, with comparable oncologic activity to that observed in the phase 3 VISION trial.