(UroToday.com) The 2026 American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL, will host the Prostate, Testicular, and Penile Cancer – Posters Session. Dr. Praful Ravi will present Abstract 5102: Quantitative results from PSMAtrack: A prospective study evaluating change in PSMA-PET during initial systemic therapy for mHSPC.
Achieving a PSA <0.2 ng/mL after 6 months of treatment with ADT plus an androgen receptor pathway inhibitor (ARPI), with or without docetaxel, is strongly prognostic in metastatic hormone-sensitive prostate cancer (mHSPC).1 However, less is known about the biologic significance of persistent disease detected on PSMA-PET imaging despite biochemical response. This prospective pilot study evaluated whether quantitative PSMA-PET parameters after 6 months of therapy correlate with PSA response in patients with mHSPC.
This single-institution study enrolled patients with mHSPC initiating ADT plus ARPI ± docetaxel. F18-flotufolastat PSMA-PET imaging was performed at baseline within 21 days of ADT initiation and repeated after 6 months of systemic therapy. Quantitative PSMA-PET parameters included total tumor volume (TTV), SUVmax, and SUVmean.
Among 21 enrolled patients, 20 had evaluable baseline and 6-month PSMA-PET scans. Median age was 70 years (range 60–95), median baseline PSA was 55 ng/mL (range 2–3,696), and 65% of patients had high-volume disease per CHAARTED criteria. Twelve patients (60%) received ADT plus ARPI, while 8 (40%) received triplet therapy with docetaxel.
At 6 months, median PSA was 0.29 ng/mL (range <0.02–177), and 9 patients (45%) achieved a PSA ≤0.2 ng/mL. Despite treatment, all 20 patients demonstrated persistent PSMA-avid disease on qualitative review at 6 months, with 85% showing residual disease outside the prostate. Additionally, 2 patients (10%) developed new lesions on follow-up PSMA-PET imaging.
Importantly, patients achieving a 6-month PSA ≤0.2 ng/mL demonstrated significantly lower median TTV and SUVmax values compared with those with PSA >0.2 ng/mL. Median TTV was 7.7 mL (range 0.4–79.9) versus 147 mL (range 5.9–3440), respectively (p<0.01). Similarly, median SUVmax was 8.7 (range 4.8–39.2) versus 47.4 (range 11.7–162) (p<0.01), whereas SUVmean was not significantly different between groups (5.3 vs 6.4; p=0.14).
Baseline TTV strongly correlated with 6-month PSA levels (r=0.74, p<0.01). PSA and TTV also demonstrated strong correlations both at baseline (r=0.68, p=0.001) and at 6 months (r=0.81, p<0.01), as well as for changes over time from baseline to 6 months (r=0.67, p=0.001).
Key Messages:
- Persistent PSMA-avid disease remained detectable in all patients after 6 months of ADT plus ARPI ± docetaxel, regardless of PSA response
- Patients with PSA >0.2 ng/mL at 6 months demonstrated significantly higher TTV and SUVmax values on PSMA-PET imaging
- TTV showed a strong correlation with PSA both at baseline and after 6 months of therapy
- Quantitative PSMA-PET imaging may help identify patients with suboptimal early response despite standard systemic therapy
- Six-month PSMA-PET assessment could potentially inform future consolidative treatment strategies in mHSPC
Presented by: Praful Ravi, MB, BChir, MRCP, Medical Oncologist, Assistant Professor of Medicine, Medical Director of GU Theranostics, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA
Written by: Julian Chavarriaga, MD, Clinical Assistant Professor, Urologic Oncologist, Department of Urology at Penn State Health @chavarriagaj on X during the American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL between May 29th and June 1st, 2026
Reference:- Ong M, et al. Prognostic significance of PSA>0.2 after 6-12 months treatment for metastatic hormone-sensitive prostate cancer (mHSPC) intensified by androgen-receptor pathway inhibitors (ARPI): A multinational real-world analysis of the IRONMAN registry.. J Clin Oncol 43, 5002-5002(2025). DOI:10.1200/JCO.2025.43.16_suppl.5002