Ultrasound’s New Focus

Can it Eradicate Tumors?

Science News, April 29, 2006 by Ben Harder

Fixing Fibroids

Continued from Monday’s article.

Uterine fibroids are nonmalignant tumors that can impair fertility and sometimes cause pain, heavy menstrual bleeding, and urinary frequency. The condition has traditionally been treated by surgical removal of the uterus, or hysterectomy. This approach definitively rids a woman of fibroids and relieves the pressure that the fibroids had placed on nearby tissues.

In contrast, HIFU “does not totally get rid of the fibroids,” says radiologist Fiona Fennessy of Brigham and Women’s Hospital in Boston. “This isn’t a malignant tumor. All we’re trying to do is improve symptoms”

To minimize risks such as skin burns and damage to healthy internal tissues, radiologists destroy only the center of the fibroid and don’t attempt to heat the surrounding area, called the margin, Fennessy says.

However, because the blood vessels that support a fibroid are concentrated near its core, destroying the center usually eliminates part of the margin, says gynecologist Phyllis Gee, director of the North Texas Uterine Fibroid Institute in Plano.

To evaluate HIFU’s success, Brigham and Women’s researchers led by gynecologist Elizabeth A. Stewart treated more than 100 women who had fibroids. The team used a machine made by InSightec Ltd. of Haifa, Israel, that incorporates an ultrasound transducer into a magnetic-resonance (MR) scanner.

During treatment, a sedated woman lies facedown on the bed of the scanner. Beneath her abdomen, the ultrasound transducer aims and fires away for up to 3 hours while the MR scanner lets doctors monitor tissue temperature and fibroid position.

Most patients experience a “mild level of pain” during and immediately after procedure, Stewart says.

Stewart’s team reported in the January Fertility and Sterility that 71 percent of the patients treated have a significant reduction in fibroid symptoms for at least 6 months, and 51 percent experience that improvement for at least a year. HIFU doesn’t produce sufficient relief for all women, however. Seventeen percent of the volunteers sought another treatment, such as hysterectomy, within a year, Stewart says.

Women treated with HIFU missed an average of 1.4 days of work after the operation, Stewart says. That compares with 18.9 missed days among women treated by hysterectomy for similar fibroids, Stewart reported in Jerusalem last June to the Israel Society of Obstetrics and Gynecology.

To measure the benefit 3 years after treatment, Gee is leading a new study that will track 70 women with fibroids who received HIFU. InSightec funded both studies.

After reviewing preliminary clinical data, the U.S. Food and Drug Administration in late 2004 approved the InSightec equipment for clinical use in treating fibroids.

Please come back on Friday to continue the article.