The Oxford HIFU Clinical Trials

There have been many prototype devices used both in the UK and worldwide; these have in general been "home-made" devices.

The first HAIFU devices installed in the Far East have been extensively used for the treatment of patients. Unfortunately, although these treatments have been highly successful, full information about the clinical history of the patients is not always available and full follow up has often been difficult. There has therefore been a need for exacting trials to be undertaken. The Oxford trials using protocols approved by the Ethics Committee of the Oxford Radcliffe Hospitals Trust and the Medical Devices Agency, are designed to meet this need.

The Oxford trials are being carried out on the HAIFU System (JC model), which is far in advance of anything similar commercially available, so far as its design and technology are concerned. It also benefits from the widespread clinical evidence accrued in the Far East.

A single therapeutic exposure typically leads to a volume of tissue damage, which is ellipsoidal in shape, approximately 13mm long, and 1.5mm in diameter. This is called a lesion. Larger tissue volumes can be ablated (destroyed) either by placing successive exposures side by side, or by scanning the focal region steadily across the target tissue in sequential strips. The mode of treatment is determined in each case by a detailed planning session prior to the therapeutic session. Planning and treatment times will vary with the size of the tumour to be treated. Planning can normally take place within 1 hour, and treatment of small tumours can be achieved in a similar time, although larger tumours can take several hours to treat, and sometimes require more than one treatment session.

Four clinical trials have been undertaken in Oxford two in liver, and two in kidney. The preliminary results have been published and a wide selection of papers on the technology are available at Published Papers.

Currently further patients are being sought, so that the trials can be completed and application made for NICE approval. For details see Trial Patient Information.