High Intensity Focused Ultrasound (HIFU) is a definitive treatment for localized prostate cancer that is currently utilized most in Europe and Japan but it not yet approved by the FDA for this indication. Within the armamentarium of definitive prostate cancer therapies it is unique as it is truly non-invasive and does not involve incision or excision. The purpose of this paper is to review the scientific foundation of the technology as well as the clinical outcomes of commercially available devices. The scientific foundation of HIFU is reviewed in terms of how it has resulted in the development of commercially available equipment. MEDLINE was used to search the medical literature for publications pertaining to HIFU for prostate cancer as a primary therapy in terms of clinical outcomes. Biochemical disease free rates as well as negative biopsy rates are reviewed. Different engineering optimization strategies in the face of technicalities inherent to HIFU for prostate cancer have led to the development of two distinct commercially available devices. Each has their own merits and limitations. HIFU provides excellent biochemical and local control and results appear to be durable. Clinical outcomes are similar for the two technologies developed but are difficult to compare due to different lengths of follow-up and varying patient populations. HIFU is a technically advanced definitive local therapy for prostate cancer. Short and medium term results are encouraging and its role as a primary therapy for prostate cancer continues to be defined as more results become available.

Key words: High Intensity Focused Ultrasound; HIFU; Prostate cancer; and Local therapy.