Phase I/II trial of high intensity focused ultrasound for the treatment of previously untreated localized prostate cancer.

PURPOSE We examined the safety and potential efficacy of transrectally delivered high intensity focused ultrasound for the full gland ablation of previously untreated localized prostate cancer. MATERIALS AND METHODS A total of 20 patients with localized prostate cancer underwent 1 to 3 high intensity focused ultrasound treatments of the prostate. The primary outcome was safety and the secondary outcomes were prostate specific antigen, prostate biopsy and quality of life measures. RESULTS A total of 19 patients had complete followup. Serious adverse events related to treatment were limited with the most common adverse event being transient urinary retention more than 30 days in duration in only 10% of patients. Rectal injury occurred in 1 patient. With 1 to 3 treatments 42% of the patients achieved prostate specific antigen less than 0.5 ng/ml and a negative prostate biopsy. CONCLUSIONS High intensity focused ultrasound in patients with previously untreated prostate cancer is generally well tolerated and it has the potential to completely ablate the prostate gland. With further refinement of the optimal treatment dose and technique this technology has the potential to be an effective form of therapy for localized prostate cancer.