What is high intensity focused ultrasound?  

High intensity focused ultrasound (HIFU) is a noninvasive medical technology that uses focused ultrasound waves to generate heat and destroy tissue in small areas of the body.  

HIFU is different than imaging ultrasound, which is often used in medicine as a diagnostic tool. Imaging ultrasound uses low intensity sound waves to create real-time images or video of internal organs and other parts of the body.  

The ultrasound waves used in HIFU are delivered at a much higher intensity than those used in imaging ultrasound. When the waves in HIFU are focused on a specific area of the body, they can generate enough heat to destroy harmful tissue, such as a brain malformation or tumor that is causing an issue for the child.  

At Children’s Hospital of Philadelphia, our expert neurosurgeons are using HIFU to treat patients with epilepsy. It allows them to precisely target areas deep in the brain while minimizing damage to surrounding healthy tissue. This can lead to fewer side effects. 

What benefits does HIFU offer patients? 

• Noninvasive – The procedure doesn’t require incisions. This reduces the risk of infection and other surgical complications and results in less postoperative pain than more invasive procedures such as traditional open brain surgery. 
• Precise – HIFU is more precise than open surgery and other minimally invasive surgeries used to treat seizures, such as laser ablation. This is important for children, whose anatomy is small and whose brain malformations or tumors may be very close to parts of the brain that are important for learning and memory. With HIFU, we can avoid the loss of function that sometimes comes after more traditional surgery. 
• Shorter recovery time – Patients recover more quickly and can resume normal activity sooner compared to traditional surgery. 

Who is a candidate for HIFU? 

HIFU is offered on a case-by-case basis. Candidates for HIFU are carefully screened and selected based on patient history, their specific epilepsy diagnosis, and their anatomy. We will perform a thorough evaluation, including imaging studies like MRI, to identify the target area in the brain and assess overall suitability for the procedure. 

Children with very small hypothalamic hamartoma, whose seizures aren’t controlled by medication and who need a treatment option more precise than laser ablation and open surgery to disconnect or remove the hamartoma, may be candidates for HIFU.  

The team in CHOP’s Neuroscience Center is currently investigating expanding use of HIFU to treat brain tumors and movement disorders like dystonia. 

How does it work? 

During HIFU, a specialized transducer (which generates the ultrasound waves) is placed on the patient’s scalp, aligned with the target area identified on an MRI. The HIFU system sends out strong ultrasound waves focused on that specific area. These waves create enough heat to destroy the targeted brain tissue. The ultrasound beams can pass through layers of tissue (such as skin and other portions of the brain), leaving them unharmed, until they reach their target. 

The treatment is usually given in short bursts, which allows the surgeon and team to very carefully monitor how well it’s working and control how much energy is used. 

Why choose CHOP for high intensity focused ultrasound? 

At Children’s Hospital of Philadelphia (CHOP), the goal of treatment is to stop symptoms from interfering with a child’s normal growth and development and improve overall quality of life, in the least invasive way, with as few treatment-related side effects as possible.  

Our Neuroscience Center is the only pediatric center in the region offering HIFU. We offer HIFU to appropriate candidates because it is extremely precise. This helps avoid unintended injury to important areas of the brain that control learning and memory, which leads to increased safety and a better outcome. It can allow us to get rid of a child’s drug-resistant seizures and minimize damage to surrounding tissues of the brain.