OBJECTIVE: To investigate the efficacy and safety of extracorporeal prostatic tissue ablation using high-intensity focused ultrasound (HIFU) in vivo in animals, and in a clinical feasibility study in men, as this is an investigational minimally invasive treatment alternative for locally confined prostatic carcinoma, but may have significant side-effects. PATIENTS, MATERIALS AND METHODS: Ultrasound (1.04 MHz excitation frequency) was generated by an extracorporeal cylindrical piezo-ceramic element and focused by a paraboloidal reflector to a focal size of 32 x 4 mm. The focal distance and aperture diameter were both 100 mm. HIFU was applied extracorporeally at different intensities and pulse duration (up to 6 s) to 11 dog prostates in vivo (median intensity 1192 W/cm2) and eight patients (median intensity 3278 W/cm2, range 2384-3576) under general anaesthesia. The lesions were assessed macroscopically and histologically after HIFU and any side-effects evaluated. RESULTS: Thermoablation was feasible in vivo and in all patients. Macroscopic analysis and histology showed sharply demarcated coagulative necrosis. Side-effects, including skin and rectal burns, occurred only after transvesical application in the in vivo study. There were no side-effects in patients after perineal application. CONCLUSION: Extracorporeal HIFU is technically feasible and induces sharply demarcated tissue damage in the prostate. From the early results of this phase 1 study, the perineal approach seems to be safe.
OBJECTIVE: To investigate the efficacy and safety of extracorporeal prostatic tissue ablation using high-intensity focused ultrasound (HIFU) in vivo in animals, and in a clinical feasibility study in men, as this is an investigational minimally invasive treatment alternative for locally confined prostatic carcinoma, but may have significant side-effects. PATIENTS, MATERIALS AND METHODS: Ultrasound (1.04 MHz excitation frequency) was generated by an extracorporeal cylindrical piezo-ceramic element and focused by a paraboloidal reflector to a focal size of 32 x 4 mm. The focal distance and aperture diameter were both 100 mm. HIFU was applied extracorporeally at different intensities and pulse duration (up to 6 s) to 11 dog prostates in vivo (median intensity 1192 W/cm2) and eight patients (median intensity 3278 W/cm2, range 2384-3576) under general anaesthesia. The lesions were assessed macroscopically and histologically after HIFU and any side-effects evaluated. RESULTS: Thermoablation was feasible in vivo and in all patients. Macroscopic analysis and histology showed sharply demarcated coagulative necrosis. Side-effects, including skin and rectal burns, occurred only after transvesical application in the in vivo study. There were no side-effects in patients after perineal application. CONCLUSION: Extracorporeal HIFU is technically feasible and induces sharply demarcated tissue damage in the prostate. From the early results of this phase 1 study, the perineal approach seems to be safe.
Authors: Gabe E Owens; Ryan M Miller; Sonal T Owens; Scott D Swanson; Kimberly Ives; Greg Ensing; David Gordon; Zhen Xu Journal: Pediatr Cardiol Date: 2011-09-11 Impact factor: 1.655
Authors: Timothy L Hall; Christopher R Hempel; Kirk Wojno; Zhen Xu; Charles A Cain; William W Roberts Journal: Urology Date: 2009-07-22 Impact factor: 2.649