Benjamin H. Lowentritt, MD, FACS, Highlights 18F-rhPSMA-7.3 Detection Rates by Subgroup in Suspected Recurrent Prostate Cancer

PSMA-targeting PET ligand 18F-rhPSMA-7.3 yielded high detection rates for patients with recurrent prostate cancer regardless of factors such as PSA levels, PSA doubling time, or Gleason scores, according to Benjamin H. Lowenritt, MD, FACS.

CancerNetwork® spoke with Benjamin H. Lowenritt, MD, FACS, a practicing urologist at Chesapeake Urology in Baltimore, Maryland, about findings from the phase 3 SPOTLIGHT study (NCT04186845), examining the impact of clinical factors on the detection rate of 18F-rhPSMA-7.3 in suspected recurrent prostate cancer, that were presented at the 2022 American Society for Radiation Oncology (ASTRO) Annual Meeting. According to Lowenritt, the agent produced high detection rates across patient subgroups based on factors such as prostate-specific antigen (PSA) level, PSA doubling time, and initial Gleason scores.


What we know about patients who recur is that we do see all different patterns of recurrence, some that happen more quickly, and some that happen over more of a time period. We also find the patients at different points—both specifically with their PSA levels, as well as their PSA doubling time—may have had a history of higher or lower grade cancer at their initial diagnosis. We looked at all of these [factors], [including] the PSA level, the PSA doubling time, their initial Gleason score, and whether they had surgery or radiation initially, and there was an overall very high level of performance and detection rates across all of those subgroups.

There certainly is a component of the absolute PSA level where you see the higher the PSA, the higher the detection rate but in the entire cohort that was studied—where we assessed detection rate data using a majority of blinded central readers—83% of patients who were imaged had disease detected. All of this was very positive and shows the value of having this novel PET agent in identifying sites of recurrence.


Lowentritt, B. Impact of clinical factors on 18F-rhPSMA-7.3 detection rates in men with recurrent prostate cancer: findings from the phase 3 SPOTLIGHT study. Presented at 2022 American Society for Radiation Oncology Annual Meeting (ASTRO); October 23-26, 2022; San Antonio, TX. Abstract 1049. Accessed November 3, 2022.