High-intensity focused ultrasound: where are we and where to from here?

High-intensity focused ultrasound (HIFU) has evolved significantly from early work treating cerebral lesions. The ability to treat deep soft-tissue lesions without damaging superficial structures led to it being used for prostate cancer treatment both in the primary and salvage setting. Primary HIFU treatment for prostate cancer leads to 5-year disease free survival rates of up to 70-80% in selected patients with little morbidity; however, comparative studies with established treatment modalities are lacking. Salvage treatment with HIFU leads to significantly more morbidity than primary treatment yet the morbidity appears the same or less than other salvage treatments following external-beam radiation treatment. We believe that with the development of more advanced imaging techniques combined with multimodality prostate imaging that HIFU's future lies in focal treatment of prostate cancer.