Focal Therapy Eligibility Determined by MRI/US Fusion Biopsy: Beyond the Abstract

The Executive Summary of the new AUA/ASTRO/SUO Guidelines for Clinically Localized Prostate Cancer recognizes focal therapy as a selected management option that may be implemented in appropriately selected men. However, long term oncological efficacy remains unknown and limits the utility of these treatments in the face of better studied treatment modalities.
A critical barrier to robust testing of focal therapy treatments is appropriate patient selection criteria, which are not clearly established. Another is knowing a priori which patients will benefit from partial treatment, with some arguing for focal therapy as an alternative to surgical intervention, and others for focal therapy as a complement to active surveillance. 

In the present study, we sought to study the impact of patient selection criteria determined by MRI/US fusion biopsy on focal therapy eligibility and to compare our findings with whole organ pathology in a subset of men who underwent radical prostatectomy. 454 men who met intermediate risk eligibility criteria were included in the study, and of these, 64 underwent radical prostatectomy. We found that more than a third of men diagnosed with prostate cancer using MRI/US fusion biopsy were eligible for focal therapy using intermediate risk criteria.

The importance of determining eligibility using fusion biopsy with both targeted and template cores was made evident by the improved concordance with whole mount histology compared to targeted biopsies alone. However, most importantly, we discovered that improved criteria need to be established in order to determine focal therapy eligibility with improved accuracy. For now, focal therapy remains a promising treatment modality limited primarily by appropriate patient selection, and if nothing else warrants continued scientific investigation. 

**We would like to especially acknowledge the contributions of Frederick J. Dorey, not only as a co-author on the present study and to the field of urology, but more importantly as a friend and teacher to the many students and residents who worked with him. 

Written by: Nima Nassiri, M.D

Read the Abstract

References:

AUA 2017: AUA/ASTRO/SUO Guidelines 2017: Localized Prostate Cancer Intermediate-Risk