New research outlines the role of prostate-specific membrane antigen (PSMA) positron-emission tomography/computed tomography (PET/CT) in the detection and management of recurrent disease in prostate cancer patients. In initial results from a multicenter trial assessing the impact of F-18 DCFPyL PSMA PET/CT, a PET-directed change in management was observed in two-thirds of patients. The research was presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2020 Virtual Annual Meeting and was published by Metser et al in The Journal of Nuclear Medicine.
Approximately 30% to 40% of men experience a biochemical recurrence of prostate cancer in which their prostate-specific antigen (PSA) levels rise after initial treatment.
Study Methods
DCFPyL (PSMA) PET/CT has been shown to be effective in diagnosing patients with prostate cancer. To assess its impact on the management of patients with suspected limited recurrent prostate cancer after primary therapy, researchers conducted a prospective, large-scale multicenter trial. The study included 410 men who had biochemical failure after primary therapy, had either no or limited disease on conventional imaging (CT and bone scintigraphy), and had undergone one of several prostate cancer treatments.
Effectiveness of PSMA PET/CT
KEY POINTS
- PSMA PET/CT identified disease in more than half of the men in whom CT and bone scan scintigraphy was negative.
- PSMA PET-directed management changes were recorded in 66% of the patients.
- The most common changes were conversion from observation or systemic therapy to surgery or radiation, or the addition of nodal-directed therapy to salvage surgery or radiation.
PSMA PET/CT identified disease in more than half of the men in whom CT and bone scan scintigraphy was negative. Additional sites of disease were observed in nearly two-thirds of patients in whom limited metastases were detected prior to PET. PSMA PET-directed management changes were recorded in 66% of the patients. The most common changes were conversion from observation or systemic therapy to surgery or radiation, or the addition of nodal-directed therapy to salvage surgery or radiation.
“The identification of extent of recurrence and specific sites of recurrence is crucial in determining the most appropriate mode of therapy for these men,” noted first study author Ur Metser, MD, Professor of Radiology at the University of Toronto. “Findings from this study add to the body of evidence on the utility of PSMA PET in the management of prostate cancer.”
He continued, “At this time, PSMA PET remains investigational in North American jurisdictions. Evidence generated from this study will help in seeking regulatory approvals to make molecular imaging with [F-18 DCFPyL] widely available and will pave the way for clinical studies that incorporate PSMA PET as a treatment planning tool to assess ultimate impact on patient outcomes.”
Disclosure: For full disclosures of the study authors, visit jnm.snmjournals.org.
