Thanks to expanded commercial guidelines for noninvasive magnetic resonance focused ultrasound treatment of uterine fibroids, doctors are now able to destroy more of the tumour and achieve longer lasting effects, researchers said here at the 55^th annual clinical meeting of the American College of Obstetricians and Gynecologists (ACOG).

"As we continue to analyse data from various protocols using magnetic resonance focused ultrasound we are seeing that the damage to the fibroid tumour increases, and as the tumour is destroyed the patients feel better," said Phyllis Gee, MD, medical director, North Texas Uterine Fibroid Institute, Plano, Texas, United States.

When researchers used the focused ultrasound technique and began experiments in attacking uterine fibroids with the device, regulators required limited use of the treatment so that it could be evaluated serially to ensure that there was no harm to the patient, she explained.

For example, in the pivotal studies, doctors were limited to treated 33% of the tumour volume or a maximum of 100 cc of one fibroid and 150 cc of multiple fibroids. The treatment time was limited to two hours and the treatment could not come closer than 1.5 cm from the endometrium. In addition, treatment could not come closer than.5 cm from the fibroid capsule, Dr. Gee said at her poster presentation May 8^th.

In the most recent series of patients, she reported that treatment volume was now limited to 50% of all fibroids; there was no restriction on the total volume of fibroids that could be destroyed; treatment time was now extended to a maximum of three hours; there was no limitation on how close to the endometrium the treatment could approach, and no restrictions were made on how close to the fibroid capsule the doctors could treat.

The present study enrolled 73 African American women, she said, responding to Food and Drug Administration suggestions that more African Americans be included in the trials. The previous studies, including the 96-patient pivotal trial has a sparse representation of minorities, Dr. Gee said.

She demonstrated that most of the symptom relief in this series occurred within the first three months following treatment, but the impact of the treatment lasted at least 36 months.

In the most recent study, 86% of women being treated under the commercial guidelines that extend the treatment envelope were able to achieve clinically meaningful 10-point or greater reductions in the Symptom Severity Score, a validated measure of pain and discomfort caused by the fibroids.

As a reflection of that achievement, the percentage of women seeking alternative treatment is dramatically lower than treatment under earlier protocols. In the first trial, 49% of women were seeking other forms of treatment within 36 months and 37% of women did so after 24 months.

In the current trial, 10% of women sought additional treatment after 24 months, Dr. Gee said.

"This data confirms improved efficacy and durability of magnetic resonance focused ultrasound surgery of uterine leiomyoma with expanded commercial guidelines," she said. "These enhanced treatments result in greater symptom relief and less need for alternative treatments."