HIFU

Surgeons in Zurich have successfully demonstrated the safety and efficacy of a revolutionary brain surgical procedure. The method allows surgeons to carry out fully non-invasive brain interventions, even on an out-patient basis, using high-intensity focused ultrasound (HIFU) guided by magnetic resonance imaging (MRI).

HIFU  (pronounced high foo) has been used for the treatment of uterine fibroids and tumors of the prostate gland for several years. However, its application to the brain through the intact skull for non-invasive neurosurgery seemed impossible until now.

The researchers have successfully treated ten patients using transcranial HIFU since September 2008. The new technology opens up procedures for a variety of brain diseases, including brain tumors.

The HIFU beams pass straight through the patient's skull and are focused within the brain into a point 3-4 mm in diameter. This allows the surgeon to guide the ultrasound beam and to then ablate tumor or other diseased tissue at a very precise location in the brain. The ultrasound beam produced by 1024 transducers raises the temperature of the tissue through a sequence bursts lasting 10-20 seconds.

The results can be seen on a live map as the ablation takes place. The procedure can last several hours, but is performed without anesthesia. The patient is fully conscious through the procedure and so can respond to requests to move or speak and allow the surgeon to double-check that healthy brain tissue is not being damaged. It also avoids pre-operative medication risks associated with anesthetics, and reduces the time the patient must spend in hospital following surgery.

Researchers are also investigating the possibility of using HIFU to treat breast, liver, and bone cancers. Although many countries have been using HIFU for years, with thousands of successful procedures completed, the US only has a relatively small number of HIFU clinical studies in process, and it is not completely approved for all procedures, yet.