Highlights from ASCO GU 2026: An Intra-patient Contemporaneous Comparison of 18F-piflufolastat and 18F-flotufolastat Urinary Radioactivity and Local and Pelvic Region Detection Rates in Men with Low Prostate-specific Antigen Biochemical Recurrence of Prostate Cancer after Radical Prostatectomy

How to cite: Helfand BT. Highlights from ASCO GU 2026: An Intra-patient Contemporaneous Comparison of 18F-piflufolastat and 18F-flotufolastat Urinary Radioactivity and Local and Pelvic Region Detection Rates in Men with Low Prostate-specific Antigen Biochemical Recurrence of Prostate Cancer after Radical Prostatectomy. Grand Rounds in Urology. February 2026. Accessed Feb 2026. https://grandroundsinurology.com/an-intra-patient-contemporaneous-comparison-of-18f-piflufolastat-and-18f-flotufolastat-urinary-radioactivity-and-local-and-pelvic-region-detection-rates-in-men-with-low-prostate-specific-antigen

Summary

E. David Crawford, MD, Editor-in-Chief of Grand Rounds in Urology and Professor of Urology, University of California, San Diego, San Diego, California, and Brian T. Helfand, MD, PhD, Chief, Division of Urology and Clinical Professor, NorthShore University HealthSystem, Evanston, Illinois, review a head-to-head comparison of two prostate-specific membrane antigen positron emission tomography (PSMA PET) radiotracers in men with biochemical recurrence after radical prostatectomy.

Fifty-five patients underwent imaging with both fluorine-18 flotufolastat and fluorine-18 piflufolastat. Median prostate-specific antigen (PSA) levels were approximately 0.28 ng/mL, representing a population frequently encountered in clinical practice.

The study evaluates whether PSMA PET agents are interchangeable. Although all target PSMA, molecular backbone differences and urinary excretion patterns may affect pelvic visualization.

Fluorine-18 flotufolastat demonstrated improved detection of local recurrence and lymph node disease at low PSA levels compared with fluorine-18 piflufolastat. In men with PSA levels below 0.2 ng/mL, more than one-third had positive scans. Overall detection rates at low PSA levels were higher with flotufolastat. Improved lesion detection may alter salvage radiation targeting and influence decisions regarding lymph node coverage or the addition of androgen deprivation therapy.

Dr. Helfand emphasizes that imaging results must be integrated with PSA kinetics and clinical judgment. Improved lesion detection may influence decisions regarding salvage radiation fields, lymph node inclusion, and the addition of androgen deprivation therapy.

Limitations include the highly selected post-prostatectomy population and the industry-sponsored nature of the trial. Additional studies are needed to evaluate biologic differences, the impact of prior or planned hormone therapy, and optimal tracer selection across clinical settings.