MR guided Focused Ultrasound Surgery

What is MR guided Focused Ultrasound Surgery?

Imagine using a magnifying glass to focus the sun's energy on a single point to create a flame to burn a leaf. The focused ultrasound energy is directed at a small volume of the myoma (fibroid), raising its temperature high enough to cause thermal ablation (killing of the cells) without impacting other tissues. Pulses of energy are repeated until the entire volume is treated.

MR guided Focused Ultrasound Surgery is an outpatient, non-invasive procedure which uses high doses of focused ultrasound waves to destroy uterine myoma (fibroids), without affecting any of the other tissues around the myoma (fibroid). The procedure is conducted in a magnetic resonance imaging (MRI) scanner which helps the physician "see" inside the body to pinpoint, guide, and continuously monitor the treatment.

What does the MR guidance provide?

Magnetic resonance imaging (MRI) is an advanced diagnostic technology which provides 3D imaging of internal organs without radiation. The MR guided FUS treatment uses the MR images to identify where the myoma (fibroid) is and what portion has been treated, without the need for any incisions. It also provides real time feedback about temperature changes of the treated myoma to make sure that the fibrotic tissue has been ablated, or destroyed.

If you require treatment for your myoma (fibroid) related symptoms, but want to avoid surgery and preserve your uterus, consult your doctor. During this consultation your doctor will ask you questions about your myoma (fibroid) symptoms, general health and medical history. You will also have routine blood work, an internal gynecological examination and MR imaging of your myoma. Based on this information your doctor will decide if you are a candidate for MR guided FUS.

What will happen during the procedure?

During the procedure you lie on your stomach on a patient table that fits into a standard MRI scanner.

First, the doctor identifies the myoma (fibroid) on MR images taken of your pelvic region. Then, after detailed planning, high energy focused ultrasound waves heat a small spot in the uterine myoma (fibroid) to a temperature of up to 85^oC. During the pulse or sonication, which lasts about 15 seconds, the doctor monitors the progress and reviews temperature-sensitive images. Since each sonication treats a very small volume, this process will be repeated until the required volume is treated, typically about 50 times. The procedure lasts about 3 hours depending upon the size and number of myomas (fibroids) treated.

Following the treatment, the body gradually flushes out the treated tissue over a period of months.

What should I expect during the treatment?

Before treatment you are given a sedative and pain medication to help you relax. You lie on a patient table and are made comfortable before starting treatment. The treatment takes place with you lying on the patient table inside the MR scanner. Your clinical team will be in the next room with two-way communication using a microphone and a speaker. The doctor will inform you when images are being acquired (scanning) and when the system is sonicating (treatment).

During treatment, it is normal to feel a warming sensation in the pelvic region. You will be given a safety stop button that allows you to immediately stop the sonication if the treatment becomes painful.

You are conscious the entire time and provide feedback during the procedure to the physician. Afterwards you'll be asked to rest for a few hours in the clinic, while the mild sedation wears off. Then you'll be able to go home and resume normal activity.

Read a UK Study examining the cost-effectiveness of MRgFUS fibroid treatments

Learn more about focused ultrasound.