PSMA-PET/CT Findings in Patients With High-Risk Biochemically Recurrent Prostate Cancer With No Metastatic Disease by Conventional Imaging

The phase 3 randomized EMBARK trial evaluated enzalutamide with or without leuprolide in high-risk nonmetastatic hormone-sensitive prostate cancer. Eligibility relied on conventional imaging, which underdetects metastatic disease compared with prostate-specific membrane antigen-positron emission tomography (PSMA-PET).

To describe the staging information obtained by PSMA-PET/computed tomography (PSMA-PET/CT) in a patient cohort eligible for the EMBARK trial. Design, Setting, and Participants: This post hoc, retrospective cross-sectional study included 182 patients from 4 prospective studies conducted from September 15, 2016, to September 27, 2021. All patients had recurrent prostate cancer after radical prostatectomy (RP), definitive radiotherapy (dRT), or salvage radiotherapy (SRT). Analysis was performed from January 2023 to July 2024. Exposures: Patients included had increasing prostate-specific antigen (PSA) levels greater than 1.0 ng/mL (after RP and SRT) or 2.0 ng/mL above the nadir value (after dRT), PSA doubling time of 9 months or less, and a serum testosterone level of 150 ng/dL or greater. Exclusion criteria were distant metastatic disease on radiographic imaging and prior hormonal or systemic therapy. Main Outcomes and Measures: Staging information obtained by PSMA-PET/CT in patients with nonmetastatic disease according to conventional imaging.