MEDICAL DEVICE INNOVATION - Medical Device Daily

MEDICAL DEVICE INNOVATION 2010
ExAblate uses ultrasound as
an aid in cutting cancer pain
By ROB KIMBALL
Medical Device Daily Staff Writer
Of the many devastating side effects of metastatic cancer,
bone pain seems the most common. Almost all patients
with metastatic prostate cancer have skeletal metastases
and 90% of patients with progressive breast cancer develop
these painful and debilitating lesions.
Current pain treatments consist of systemic therapy
(analgesics, chemotherapy, hormonal therapy and bisphosphonates)
and local treatments (radiation, surgery and
more recently, radio frequency ablation).
One company is taking on the challenge of alleviating
the pain, and the positive results are becoming evident in
studies. InSightec (Tirat Carmel, Israel) reported that new
publications show that magnetic resonance-guided
focused ultrasound (MRgFUS) with the ExAblate system has
the potential to be an effective noninvasive pain-relieving
treatment for tumors that have spread to the bones (bone
metastases).
The results of a 31-patient study appear in the Nov. 11
online issue of Annals of Surgical Oncology, while data
from an 11-patient subgroup analysis of that study were
published separately in the October issue of Radiology.
“We believe these early results provide substantial
rational for our ongoing pivotal study,” Nadir Alikacem,
InSightec’s VP of global regulatory affairs/chief regulatory
officer, told Medical Device Daily.
“These patients are in the final stages of cancer and we
believe it’s vital to maintain the quality of their lives without
the side effects associated with radiation and analgesics,”
he said. “Bone metastases are the leading cause of
cancer pain and we believe that ExAblate may provide
these patients a non-invasive, radiation free treatment.”
Alikacem added: “Our goal is not to cure their cancer,
but to help them live out the rest of their lives without suffering
from their bone pain.”
During the ExAblate treatment, the physician uses MRI
with registered CT images to visualize the patient’s anatomy
and then aims focused ultrasound waves at the tumor
to relieve the pain. The MRI allows the physician to monitor
and continuously adjust the treatment in real time. The
patient is consciously sedated to alleviate pain and minimize
motion.
The focused ultrasound waves are focused down onto
a small area of the painful bone. This causes the bone surface
to heat up and destroys the tissue. The focused ultrasound
is then targeted to another area next to the treated
location and this new area is treated.
The process is repeated several times until the nerves
in the bone surface of the painful bone tumor are
destroyed. Due to the high acoustic absorption and low
67
thermal conductivity of the bone cortex, it is possible to
use a low level of energy and still achieve a localized heating
effect that will relieve the pain while minimizing damage
to adjacent tissue, InSightec said.
“The increasing longevity of the population, along with
the rise in cancer incidence during the last decade and
ever-improving treatment outcomes for primary cancers,
contributes to the growing number of patients living with
metastatic bone disease,” said Boaz Liberman, MD, head of
orthopedic oncology of Sheba Medical Center (Tel
Hashomer, Israel) and lead author of the 31-patient analysis.
“Increasing focus on cancer patients’ quality of life has
led to a search for effective pain-relieving treatments with
fewer short- and long-term side effects,” he said. “These
preliminary results suggest that the ExAblate treatment
using MRgFUS has the potential to provide a safe and effective
noninvasive treatment for patients suffering from
painful bone metastases.”
InSightec is currently enrolling patients into an FDAapproved
Phase III pivotal study to confirm these earlier
results. It expects to enroll 148 subjects with bone metastases
who are not candidates to radiation treatments into
the study at centers throughout the U.S. and around the
world.
Alikacem shared with MDD InSightec’s plans for the
future of the ExAblate after the Phase III study is conducted.
“If the data are positive, as expected, we plan to file a premarket
application with the FDA. We also remain focused
on the uterine fibroids indication, for which the system is
currently approved and used commercially. “
He said the company also has begun an FDA Phase IV
study pertaining to fibroids. “The purpose of this multi-site
randomized clinical study is to determine if ExAblate treatment
can help women with non-hysteroscopically
resectable uterine fibroids who are diagnosed with unexplained
infertility become pregnant. Women in this study
will be randomized with myomectomy surgery,” he said.
The ExAblate is currently used commercially as a treatment
for symptomatic uterine fibroids. The system
received the CE mark for uterine fibroids in 2002 and FDA
approved the system as a treatment for symptomatic uterine
fibroids in 2004.
More than 4,500 symptomatic women have been treated
with the ExAblate to date, with 92% reporting symptom
relief up to 36-months after treatment. The ExAblate system
received CE-mark certification for pain palliation of
bone metastases in June 2007.
(This story originally appeared in the December 16,
2008, edition of Medical Device Daily)
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