new methods explored to localize nonpalpable breast lesions kate johnson december 11, 2014 san antonio — new and better methods are nee
New Methods Explored to Localize Nonpalpable Breast Lesions
Kate Johnson
December 11, 2014
SAN ANTONIO — New and better methods are needed for localizing
nonpalpable breast lesions at the time of surgical excision, according
to two researchers who presented preliminary data on alternative
methods here at San Antonio Breast Cancer Symposium (SABCS) 2014.
Both researchers say their proposed methods, one using a magnetic
tracer, and the other an electromagnetic reflector, can bypass some of
the drawbacks of current wire-guided and radioisotope- guided
localization methods.
"One third of breast cancer diagnosed annually throughout the world is
nonpalpable, and that level is likely to increase because of the
greater implementation of screening programs as well as more advanced
modalities, such as MRI, which pick up more clinically occult
lesions," said Muneer Ahmed, MRCS, a surgeon from King’s College
London, in the United Kingdom.
Currently, the most widely used method of wire-guided localization
(WGL) is seriously limited by the need for same-day wire placement and
excision, and it also faces other technical challenges resulting in a
re-excision rates as high as 50%, said Dr Ahmed. "So clearly there's a
need to try and develop an alternative technique."
Nonpalpable breast lesion.
Radioisotope techniques such as radio-guided occult lesion
localization and radioactive seed localization have emerged to address
some of the WGL drawbacks, but they too have limitations, said Charles
Cox, MD, who invented and patented the radioactive seed technique.
"The problem with radioactive material is that it's great at
localizing the cancer, but it has all the regulatory issues and the
fear factor of putting something radioactive into someone," said Dr
Cox, a surgeon from the University of South Florida College of
Medicine, in Tampa.
At the meeting, Dr Cox presented preliminary data on the SAVI Scout
surgical guidance system (Cianna Medical Inc), which uses an
intratumoral electromagnetic wave device, implanted under ultrasound
or mammographic guidance, to localize occult breast lesions with a
probe during surgery.
At the adjacent poster, Dr Ahmed's study showed preliminary results
with the MagSNOLL Trial, using an iron oxide magnetic tracer (0.5 mL,
Sienna, Endomagnetics Ltd) injected into occult breast lesions under
ultrasound guidance up to 1 week before surgery. The tracer was then
detected during surgery using a hand-held magnetometer.
In the MagSNOLL trial, among an initial 20 patients with nonpalpable
lesions, the magnetic tracer technique detected 100% of lesions, with
only two requiring re-excision because of positive margins, he said.
An additional benefit of the magnetic tracer is that it can also be
used to localize sentinel lymph nodes (SLNs), especially when used in
conjunction with patent blue dye.
Dr Ahmed’s study showed that 85% of SLNs were detected using the
magnetic tracer alone, with a 97% detection rate when blue dye was
also used.
In Dr Cox's trial, 24 patients underwent intratumoral placement of the
electromagnetic reflector under ultrasound or mammography guidance.
The reflector was placed an average of 1.1 days before surgery and was
then localized in the operating room with the use of a hand piece and
console to detect feedback.
Among the seven patients who underwent excisional biopsy and the 17
who underwent lumpectomy, the reflector and lesion were successfully
removed.
Final pathology, which was available from 19 patients, showed benign
findings in all excisional biopsy patients and clear margins in 11 of
12 lumpectomy patients. One patient had a positive margin and required
re-excision.
"I would like to see this being used for any nonpalpable breast biopsy
procedure," said Dr Cox. "The biggest issue is, how much is it going
to cost? That will be the next big hurdle ― how to bring a new device
to market and get it paid for."
The materials and devices in both studies already meet criteria for
regulatory approval in their respective countries because they are
already used either in breast cancer or other medical treatments.
Both investigators are planning larger studies.
Dr Cox's study was funded by Cianna Medical Inc for a total of $5000
for data collection from up to 25 patients enrolled locally. Materials
were provided by the company. Materials for Dr Ahmed's study were
provided by Endomagnetics Ltd. Dr Cox is a consultant and serves on
the advisory board of Cianna. Dr Ahmed has disclosed no relevant
financial relationships.
San Antonio Breast Cancer Symposium (2014): Abstracts P1-16-09 and
P1-16-10. Presented December 11, 2014.
Medscape Medical News © 2014 WebMD, LLC
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Cite this article: New Methods Explored to Localize Nonpalpable Breast
Lesions. Medscape. Dec 11, 2014.