Can 18F-Flotufolastat Bolster Detection of PCa Recurrence in Patients with Low PSA Levels After Radical Prostatectomy?

The positron emission tomography (PET) agent 18F-flotufolastat detected has a nearly 75 percent detection rate for recurrent prostate cancer in patients with prostate-specific antigen (PSA) levels of less than 1 ng/mL, according to research presented at the American Society for Radiation Oncology (ASTRO) conference.

In a recent interview, Bridget Koontz, M.D., the lead author of the post-hoc analysis from the SPOTLIGHT trial, said delayed renal clearance with 18F-flotufolastat (Posluma, Blue Earth Diagnostics) provides a unique advantage in this patient population in comparison to other imaging agents.

“Excretion into the bladder is slower (with ¹⁸F-flotufolastat) than some of the other agents out there … so you don't get sort of a cloud of urinary uptake that can blur … when we're trying to see what's happening in the prostate or in the prostate bed. That is a big advantage for low PSA patients, because they're less likely to have metastatic disease and, frankly, more likely in the post prostatectomy space to have prostate bed recurrence,” emphasized Dr. Koontz, the medical director of radiation oncology at AdventHealth Cancer Institute in Orlando, Fla.

(Editor’s note: For related content, see “Study: ¹⁸F-Flotufolastat PET Imaging Changes Treatment in 89 Percent of Patients with Prostate Cancer Recurrence,” “Recurrent Prostate Cancer and Low PSA Levels: Can an Emerging PSMA PET Agent Have an Impact?” and “Optimal Timing and Frequency of Imaging Agents Used in the Detection and Characterization of Oligometastatic Prostate Cancer.”)

In addition to an overall 69 percent detection rate in those with a pSA level of less than 1 ng/mL, the researchers found a 74 percent detection rate of PCa recurrence in patients with PSA levels between 0.5 ng/mL < 1 ng/mL. Dr. Koontz pointed out that ¹⁸F-flotufolastat maintained high detection rates with even lower PSA levels, noting a 67 percent rate in those with PSA levels 0.3 ng/mL < 0.5 ng/mL and a 68 percent rate when PSA levels were 0.2 ng/mL < 0.3 ng/mL.

(Editor's note: For additional content on prostate cancer imaging, visit here.)

For more insights from Dr. Koontz, watch the video below.

Reference

1. Koontz BF, Lowentritt B, Jani AB, et al. ¹⁸F-flotufolastat detection rates in the pelvis region for patients with prostate cancer recurrence after radical prostatectomy and PSA levels < 1 ng/mL: data from the phase 3 SPOTLIGHT study. Presented at the American Society for Radiation Oncology (ASTRO) 2024 Annual Meeting, September 29-October 2, 2024. Available at: https://www.astro.org/meetings-and-education/micro-sites/2024/annual-meeting .