How to cite: George AK. “Patient Selection: Fusion and Confirmatory Biopsy.” October, 2025. Accessed Oct 2026. https://grandroundsinurology.com/patient-selection-fusion-and-confirmatory-biopsy/
Summary
Arvin K. George, MD, Director Prostate Cancer Programs, Associate Professor of Clinical Urology, Johns Hopkins University, Baltimore, Maryland, describes the information required from fusion and confirmatory biopsies to determine whether a patient is a suitable candidate for focal therapy. He outlines that fusion biopsy provides both imaging and histologic data. Imaging allows for the localization of the lesion, assessment of local staging, including extracapsular extension and seminal vesicle invasion, and identification of the number and distribution of suspicious regions based on prostate imaging reporting and data system (PI-RADS) scoring. It also offers insight into the accessibility of the target based on the anticipated treatment approach. It provides an understanding of anatomy when transperineal biopsy techniques overlap with planned interstitial therapies.
From a pathologic standpoint, fusion biopsy must reliably identify clinically significant prostate cancer and exclude out-of-field clinically significant disease, which represents a major risk of early failure. Dr. George reviews prostatectomy data demonstrating that magnetic resonance imaging (MRI) detects only a portion of all cancer foci and that sensitivity improves but remains imperfect for Grade Group 2 or higher disease. He explains key limitations of enriched prostatectomy cohorts and the per-lesion design of PI-RADS.
He discusses confirmatory diagnostic studies, which demonstrate strong sensitivity but limited specificity for MRI when compared with transperineal mapping biopsy. He presents data evaluating the concordance between fusion biopsy-based focal therapy eligibility and whole-mount pathology, showing that although fusion biopsy identifies many candidates, whole-mount analysis reveals a lower proportion of truly eligible patients. Adding systematic biopsy improves accuracy from approximately 54% to 75%.
Dr. George outlines settings in which a confirmatory biopsy is beneficial, including systematic biopsy only, concern for multifocality or undergrading, discordant clinical information such as prostate-specific antigen (PSA) density or prostate-specific membrane antigen (PSMA) findings, and uncertainty regarding outside hospital biopsy. He argues that both imaging and biopsy are imperfect and that systematic biopsy improves risk stratification and selection for focal therapy.
Frontiers in Oncologic Prostate Care and Ablative Local Therapy (FOCAL) is an outstanding program on prostate imaging, transperineal interventions, and ablative treatments for prostate cancer and benign prostatic hyperplasia. Bringing together community-based, academic, and industry partners, FOCAL offers lectures by world-renowned faculty and hands-on training workshops on in-office transperineal interventions, fusion-guided prostate ablation and state-of-the-art BPH management with novel technologies.
ABOUT THE AUTHOR
Arvin K. George, MD, serves as Director of Prostate Cancer Programs and Associate Professor (PAR) of Urology at Johns Hopkins School of Medicine in Baltimore, Maryland. He is a urologic surgeon who specializes in the diagnosis and management of genitourinary cancers. After obtaining his medical degree from the Royal College of Surgeons in Ireland, he completed his urology residency at the Smith Institute for Urology at the Hofstra North Shore-LIJ School of Medicine. He remained there to complete his endourology fellowship in New York, gaining additional subspecialty expertise in robotic, laparoscopic, and percutaneous surgery. Subsequently, he completed a urologic oncology fellowship at the National Cancer Institute of the National Institutes of Health. Dr. George’s research interests include minimally-invasive and image-guided treatments, functional prostate imaging, and focal therapy for prostate cancer. His research aims to identify appropriate use for imaging in diagnosis, risk stratification, and management of prostate cancer, including active surveillance and selection/treatment of patients with novel focal therapy modalities.
