Value of a repeat 18F-flotufolastat PET scan following a negative scan in patients with suspected biochemical recurrence of prostate cancer after radical prostatectomy

Ziel/Aim: This retrospective analysis assessed the value of a follow-up prostate specific membrane antigen-positron emission tomography (PSMA-PET) scan in patients with suspected biochemical recurrence (BCR) of prostate cancer (PCa) who had a previous negative 18F-flotufolastat (formerly known as 18F-rhPSMA-7.3) PET scan.

Methodik/Methods: Our study included data from patients who underwent a follow-up 18F-flotufolastat scan after having a negative 18F-flotufolastat scan for suspected BCR of PCa (prostate-specific antigen [PSA]≥0.2 ng/mL) after curative-intent radical prostatectomy. Two board experts classified 18F-flotufolastat-avid lesions per miTNM categories. Patient-level detection rate for follow-up scans was stratified by PSA level at second PET (ng/mL), PSA kinetics (PSA velocity [PSAvel], ng/mL/y; PSA doubling time [PSAdt], months), and absolute difference in PSA (ΔPSA) between negative first and follow-up scans. Region-level detection rates were also determined.

Ergebnisse/Results: Data from 101 patients with BCR of PCa (median age, 70 years; median PSA, 0.79 ng/mL) were retrospectively reviewed: 58 (57.4%) had 18F-flotufolastat-avid lesions. Median time between negative and follow-up PET was 326 days (range 104-1784). Patient-level detection rates increased with PSA increases, ranging from 46.4% at PSA≤0.5 ng/mL to 90.0% at PSA>2 ng/mL. Detection rates also increased with increases in PSAvel (ranging from 50.0% at PSAvel<0.5 ng/mL/y to 66.7% at PSAvel≥2 ng/mL/y) and ΔPSA (ranging from 43.1% at ΔPSA 0–0.5 ng/mL to 100% at ΔPSA>2 ng/mL). Differences in PSA level at second PET, PSAvel, PSAdt and ΔPSA between groups with/without 18F-flotufolastat uptake were statistically significant. Local recurrence was identified in 41/58 patients (70.7%); metastases were detected in the pelvic lymph nodes (20.7%; n=12/58), bone (15.5%; n=9/58), extrapelvic lymph nodes (10.3%; n=6/58), and viscera (3.4%; n=2/58).

Schlussfolgerungen/Conclusions: We show here that, follow-up 18F-flotufolastat after an initial negative scan detected recurrent lesions across PSA levels≤0.5–≥2 ng/mL in patients with suspected BCR of PCa, supporting the use of additional follow-up PSMA-PET scans in this patient group, particularly those with greater changes in PSA levels between scans.

 

Scroll to top

Publication History

Article published online:
12 March 2025