Focal magnetic resonance guided focused ultrasound for prostate cancer: Initial North American experience

Abstract

The treatment of low-risk prostate cancer is a common clinical dilemma between standard curative whole gland therapy (and its associated quality of life diminishing side effects) and active surveillance (and its low, but real, risk of progression). The goal of focal therapy in low-risk prostate cancer is to achieve the best balance between cancer control and maintenance of quality of life. Magnetic resonance-guided focused ultrasound (MRgFUS) surgery is a non-invasive thermal ablation method that integrates magnetic resonance imaging for target identification, treatment planning and closed-loop control of thermal deposition and focused ultrasound for thermal ablation of the tumour target. This novel transrectal system allows for tumour localization, targeting and monitoring of tumour target ablation in real time, while simultaneously preserving adjacent normal tissue thereby minimizing the side effects of standard curative surgical or radiation therapy. We report the first North American clinical experience of treatment of localized prostate cancer with focal MR-guided transrectal focused ultrasound (clinicaltrial.gov identifier NCT01226576).

Figures

Fig. 1

Intra-procedure image of the prostate, including the tumour registration.

Fig. 2

Post-contrast magnetic resonance image obtained immediately after treatment showing a non-perfusion area in the right gland at the treatment site.

Fig. 3

Changes in voiding and sexual function after magnetic resonance guided focused ultrasound. There were no significant changes in voiding and sexual function as measured by the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF)-15 from baseline to one week and one month.

Fig. 4

One month post-treatment, the magnetic resonance scan following contrast enhancement shows persistent area of non-perfusion in treated right aspect of the prostate.