FDA regulation of clinical high intensity focused ultrasound (HIFU) devices

In the U. S., medical devices are regulated under the authority of the 1976 Medical Device Amendments to the Food, Drug, and Cosmetic Act, with the Food and Drug Administration´s Center for Devices and Radiological Health having primary responsibility. The Act defines several regulatory paths to market depending on the complexity of the device and indications for use. For most high intensity focused ultrasound (HIFU) devices the premarket submissions include both pre-clinical and clinical data. Pre-clinical testing generally comprises ultrasound power measurements and field characterization, in vitro and in vivo temperature measurements, thermal computational modeling, and demonstrating the accuracy for targeting the region of interest and monitoring treatment progress. Protocols for clinical trials are developed by the device sponsor in conjunction with FDA medical and scientific staff. Currently there are no recognized guidance or standards documents for HIFU testing that could be used in the regulatory review process, but such work is underway within the International Electrotechnical Commission.