PSMA PET in Biochemical Recurrence

In this video case series, Dr. Louis Mazzarelli, Director of Molecular Imaging at Lawrence Memorial and Westerly Hospitals, focuses on the role of PSMA PET in biochemical recurrence (BCR) of prostate cancer following definitive therapy. The module provides a practical, guideline-based framework for identifying and localizing recurrent disease after radical prostatectomy, external beam radiation therapy, and focal ablative treatments.

Dr. Mazzarelli reviews consensus definitions of biochemical recurrence, emphasizing PSA thresholds that prompt imaging evaluation. He demonstrates how PSMA PET can localize recurrent disease at very low PSA levels, often before findings are apparent on conventional imaging. Using multiple case examples, he outlines a systematic approach to image interpretation, with particular attention to the vesicourethral anastomosis, lateral surgical margins, retrovesical space, pelvic lymph nodes, and common post-treatment pitfalls.

The presentation highlights how tracer bio-distribution—especially low urinary bladder activity with fluorine-18–labeled PSMA agents—can improve detection of subtle local recurrence near the bladder and urethra. Dr. Mazzarelli also addresses recurrence patterns after external beam radiation therapy, cryoablation, and irreversible electroporation (NanoKnife), underscoring the importance of evaluating treatment margins and untreated regions.

A central theme is clinical impact: PSMA PET transforms a rising PSA into a precise anatomic and biologic roadmap, guiding decisions regarding salvage radiotherapy, focal re-ablation, systemic therapy, or multidisciplinary tumor board referral. This case reinforces PSMA PET as a cornerstone of personalized imaging in the management of biochemical recurrence.