High Intensity Focused Ultrasound for Prostate Cancer: Clinical Results and Technological Evolution

Prostate cancer is responsible for 9% of cancer related death in European men (Black et al 1997) and it is estimated that each year there will be approximately 85,000 new cases of prostate cancer diagnosed in the European Union (Jensen et al 1990). Strategies for managing prostate cancer include deferred treatment (watchful waiting), radical prostatectomy, definitive radiation therapy and hormone therapy. Deferred treatment is utilized in patients who are expected to die of causes other than prostate cancer based on the age and health of the patient and the characteristics of their disease. Hormone therapy can delay but not stop the progression of prostate cancer and is used when the cancer has spread beyond the prostate. Definitive local therapy is employed when the disease is thought to be clinically localized and has the potential of decreasing the life of patient. There currently exists no agreement as to the ideal therapy for localized prostate cancer. Radical prostatectomy is the ideal therapy insofar as cancer control is concerned for truly localized prostate cancer. However, it is associated with significant morbidities and quality of life impact and there is no guarantee that the cancer really is completely contained within the prostate. This risk versus reward balance is unacceptable to many physicians and patients and has motivated the development of several minimally invasive therapies including brachytherapy, cryoablation and high intensity focused ultrasound (HIFU).