AUA 2018: MRI-Guided Transurethral Ultrasound Ablation in Patients with Localized Prostate Cancer: 3-Year Outcomes of a Prospective Phase I Study

San Francisco, CA (  Dr. Chin presented data from a prospective Phase I study using MRI-guided transurethral ultrasound ablation for localized prostate cancer. The basis of this technology is to use a transurethral ultrasound applicator to generate conformal thermal ablation zones, which is followed using real-time MRI thermometry for feedback control.  Because this was a Phase 1 study, the main endpoint was safety and tolerability. To this end, initial results demonstrate that erectile function and urinary tract function appear to return to baseline following treatment (via IPSS and IIEF instruments).  

Oncologically, 31% of men had clinically-significant cancer at 12 months. 6 underwent a radical prostatectomy, and cancer was mainly remaining in the periphery of the gland. This is likely a result of the methodology used for this safety study – a 3mm peripheral margin was used to improve the safety profile, and most of the residual cancers were found in this peripheral zone.  

An ongoing trial is now underway using a 1mm peripheral margin to improve oncological outcomes with a lower safety profile. Of note, this technology uses planar energy and is therefore able to treat the prostate in a segmental fashion, but not in a focal fashion that other ablative technologies are capable of. The moderator asked a thought-provoking question, asking if this technology is essentially equivalent to performing a TURP. Perhaps so, but there may still be advantages to avoiding tissue removal in some patients, and further data regarding functional and oncological outcomes from this technology would be helpful in determining its utility.  

Presented by:  Joseph Chin; London Health Sciences Center

Written by: Shreyas Joshi, MD, Fox Chase Cancer Center, Philadelphia, PA Twitter: @ssjoshimd  at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA