The ExAblate® combines magnetic resonance imaging (MRI) with concentrated ultrasound waves designed to destroy malignant and nonmalignant tissue. Patients lie face down on an MRI table equipped with a cradle housing the ultrasound transducer. The movable transducer, encapsulated in a water bath, transforms electricity into sound waves. After physicians locate the region requiring ablation, or tissue removal, through three-dimensional images, sonication begins. Similar to an inverted cone, the focused ultrasound waves enter the body, heat diseased tissue and effectively destroy tumor cells.
Through a special operating console, physicians direct sequential 20-second pulses of high-intensity focused ultrasound (HIFU) toward the targeted location. The number and size of tumors determine procedure length, which might extend to three hours. During ExAblate® treatment, patients remain in constant contact with the physician, nurses and technicians. Medical staff members closely monitor the patient's comfort level and the ablation progress. Continuous imaging illustrates cellular destruction by detecting temperature variances in body tissue during the procedure.
The MRI-guided focused ultrasound surgery heats targeted tissue heats targeted tissue up to 163.6 degrees F (71.1 degrees C), thus causing irreversible damage. Each sonic burst treats an area roughly the size of a jelly bean. During each 20-second sonication, patients report an overall warm sensation along with some discomfort, not unlike menstrual cramping in women. Some patients experience skin burns and muscle pain following the procedure. Physicians use gadolinium contrast, in combination with an MRI, following ablation in order to evaluate tumor destruction.
The ExAblate® is used in many countries around the world. Developed in Israel, the noninvasive medical device received approval from the United States Food and Drug Administration in 2006 as a viable uterine fibroid treatment. Thousands of women worldwide received ExAblate® therapy resulting in successful elimination of uterine fibroid tumors.
Patients express symptomatic relief immediately following treatment. Specialists perform the procedure on an outpatient basis, and patients can return to everyday activities within three days. The advanced technology of the ExAblate® spares patients from surgical procedures, postoperative complications and extended recovery times. Patients who have metal implants or allergies to MRI contrast media cannot undergo this treatment. Physicians advise against the procedure in obese patients or those who are unable to lie face-down for at least three hours.
Though widely used for fibroid tumors, ultrasound ablation also promises to enhance treatment options for cancer patients. European physicians have successfully treated hundreds of cancerous tumors using MRI-guided ultrasound for adenomyosis, breast cancer, prostate cancer and bone metastases. The innovative treatment might one day free cancer patients from harsh chemotherapy medications and surgical procedures. Studies also indicate that HIFU therapy might be successful in treating brain disorders, brain tumors, various neurological disorders and blood clots.
