There is limited data on PSMA PET/CT for work-up of recurrence after radical prostatectomy (RP) at low PSA values. We evaluated a PSMA PET/CT cohort of post-RP patients, focusing on patients with PSA <0. 5 ng/mL.
We identified a retrospective cohort who underwent piflufolastat F-18 PSMA PET/CT across an eleven-hospital system from 7/2021-2/2023. PSMA positivity was determined by radiology reports. Univariable and multivariable logistic regression identified factors associated with suspicious PSMA activity.
Median PSA was 0.37 ng/mL (IQR 0.15, 1.29 ng/mL), with 49% of patients overall having at least one suspicious PSMA-avid lesion. Rates of scan positivity among patients with PSA <0.2 and 0.2-0.5 ng/mL were 34% and 38%, respectively. Among all patients, 25% (104/415) had pelvic disease (prostate bed or N1), and 24% (100/415) had M1 disease. Among patients with PSA <0.5 ng/mL, prior post-operative radiation was associated with suspicious PSMA activity. In the overall cohort, age, PSA at PSMA PET/CT, and RP Gleason Grade (GG) were associated with PSMA positivity. PSADT, EAU risk, and CAPRA-S were all associated with suspicious PSMA activity.
Over one-third of patients with PSAs <0.2 ng/mL had imaging findings concerning for recurrence. Prior post-operative radiation was associated with higher rates of PSMA positivity among patients with PSA <0.5 ng/mL, and half of patients with evidence of PSMA avid distant metastatic disease underwent metastasis directed therapy. PET-PSMA imaging at low PSAs can be considered to inform salvage therapies.
The Journal of urology. 2024 Oct 18 [Epub ahead of print]
Eric V Li, Richard Bennett, Austin Ho, Clarissa Wong, Ashorne K Mahenthiran, Sai Kaushik Shankar Ramesh Kumar, Zequn Sun, Hatice Savas, Steven P Rowe, Edward M Schaeffer, Hiten D Patel, Ashley Ross
Northwestern University, Feinberg School of Medicine, Department of Urology, Chicago, IL 60611, United States of America., Indiana University School of Medicine, Department of Urology, Indianapolis, IN 46202, United States of America., Northwestern University, Feinberg School of Medicine, Department of Preventative Medicine, Chicago, IL 60611, United States of America., Northwestern University, Feinberg School of Medicine, Department of Radiology, Chicago, IL 60611, United States of America., University of North Carolina School of Medicine, Department of Radiology, Chapel Hill, NC 27599, United States of America.