Catheter-Based Ultrasound Applicators for Selective Prostate Ablation With MR-Guidance

The purpose of this study was to develop catheter-based ultrasound devices and techniques specifically for treating prostate cancer in conjunction with MRI thermal imaging to monitor and control treatment progression. Directional transurethral applicators have been designed with arrays of sectored tubular (90 deg active acoustic sector) or narrow planar transducer segments integrated with a flexible delivery catheter with a cooling balloon. Interstitial applicators (2.4 mm catheter diameter, 1.5 mm OD tubular transducers) with 180 deg active acoustic sectors have been developed specifically for transperineal implantation to treat the posterior portion of the prostate. Both heating strategies were evaluated via in vivo experiments within canine prostate. Both transurethral and interstitial treatment strategies demonstrated significant potential for selective thermal ablation of localized regions of the prostate, particularly when MRI thermal imaging is used to guide and assess treatment.