VIENNA, Austria — For a woman presenting with uterine fibroids over 4 inches in diameter, uterine artery embolization, the controversial alternative to hysterectomy, is not recommended.
Currently this patient has no alternative to traditional surgery and will lose her ability to bear children, unless she lives in London and finds her way to St. Mary’s Hospital, where Wladyslw Gedroyc, professor of Tadiology with Imperial College, is pioneering a radical technique called MRI-guided focused ultrasound (MRgFUS).
A guest of GE Healthcare (Waukesha, Wisconsin) at the European Congress of Radiology (Vienna, Austria) here, Gedroyc was on hand to present medical applications for a hybrid MRI unit that GE is developing with InSightec (Tirat HaCarmel, Israel) called the ExAblate 2000 that embeds an ultrasound transducer into the bed of the MRI magnet.
Uterine fibroids were the first application for the new machine and more than 250 patients have been treated in the past four years.
The transducer focuses energy from 5,000 to 10,000 times greater than conventional ultrasound, according to Gedroyc. At a precise pinpoint targeted in 3D with guidance of the MRI, the temperature rises to 56 degrees Celsius (130 degrees Fahrenheit) for one second, sufficient to coagulate cell proteins and destroy the cell.
Patients for the uterine fibroid procedure are treated with a hormone releasing agonist that induces a temporary medical menopause for three months and reduces the four-inch tumor by half. For the procedure, the beam is test-fired at sub-therapeutic doses, for example at body temperature, to validate the targeting. The fibroid is then successively zapped in a series of up to 52 points to destroy tissue.
A patient is able to walk away from the hospital, experiencing discomfort equivalent “to having a bad menstruation cycle for several days,” Gedroyc said. After six months the tumor has withered to just 1 inch in diameter.
Looking further ahead in tumor treatment, Gedroyc said ultrasound heating may be useful for localized drug release.
“You take a nasty, highly toxic drug that is very effective against tumors and wrap it in a micro-bubble shell the body accepts but which is heat-sensitive,” he explained. Once the body delivers the micro bubbles to the tumor through biological processes, MRgFUS can be used to blast the shells and release the chemotherapy directly on the tumor.
“We are looking for a grant to support this research right now,” he said.