(Ivanhoe Newswire) -- Interventional radiologists have opened the door to
an encouraging potential for treating the nearly 200,000 U.S. women who are
diagnosed with breast cancer each year. The procedure is called image-guided,
multiprobe cryotherapy.
"Minimally invasive cryotherapy opens the door for a potential new treatment for
breast cancer and needs to be further tested,” Peter J. Littrup, M.D.,
radiologist and director of imaging research and image-guided therapy for the
Barbara Ann Karmanos Cancer Institute in Detroit, was quoted as saying. “When
used for local control and/or potential cure of breast cancer, it provided safe
and effective breast conservation with minimal discomfort for a group of women
who refused invasive surgery or had a local recurrence and needed additional
management. This is the first reported study of successfully freezing breast
cancer without having to undergo surgery afterward to prove that it was
completely treated," Littrup added.
In the 13-patient study, no localized treatment recurrences were seen for up to
five years, no significant complications were noted and women were pleased with
the cosmetic outcomes, noted Littrup, who is also a professor of radiology,
urology and radiation oncology at Wayne State University in Detroit. Cryotherapy
was applied according to well-established freezing principles, and biopsies at
the margins of the cryotherapy site immediately after the procedure and at the
cryotherapy site in follow-up were all negative -- showing no cancer.
A
woman has about a 13 percent lifetime risk of developing breast cancer, with
women 50 years of age and older accounting for approximately 80 percent of all
breast cancers. For these women, as well as the thousands of men diagnosed each
year, breast cancer treatments can be highly effective but often require
invasive treatment options such as surgery and chemotherapy. Surgery offers the
best chance for a cure. Until long-term data are available, interventional
treatments -- such as cryotherapy, thermal ablation and laser therapy -- are
reserved for women who cannot have -- or have refused -- surgery.
In this study's cryotherapy treatment, researchers used several needle-like
cryoprobes that were evenly spaced and inserted through the skin to deliver
extremely cold gas directly to the tumor to freeze it. This technique has been
used for many years by surgeons in the operating room; however, in the last few
years, the needles have become small enough to be used by interventional
radiologists through a small nick in the skin, without the need for an
operation.
The "ice ball" that is created around the needle grows in size and destroys the
frozen tumor cells. The major benefits of cryotherapy are its superb
visualization of the ice treatment zone during the procedure, its low pain
profile in an outpatient setting and its excellent healing with minimal scar.
Breast imaging has markedly advanced by accurate improvements in breast magnetic
resonance imaging (MRI), allowing for excellent treatment planning of tumor size
and extent within the breast, as well as showing zones of destruction thoroughly
covering the tumor after cryotherapy, Littrup noted.
Surgeons and radiation oncologists have long tried to provide at least a
1-centimer margin of treatment surrounding all aspects of a localized breast
cancer, and it was important to ensure a similar "surgical margin" of lethal
temperatures beyond all tumor margins by cryotherapy in this study, said Littrup.
"The well-visualized ice margin by ultrasound CT or MR is actually only the
0-degree Celsius line, or isotherm, which is not sufficiently lethal to cancer
cells, but has unfortunately been confused with the actual treatment margin. We
made sure that the lethal isotherm of approximately -30 degrees Celsius extended
beyond all tumor margins," said Littrup.
After breast MRI and thorough consultation, patient consents were obtained for
institutional review board-approved breast cryotherapy. In 13 cryotherapy
sessions, 25 breast cancer foci were treated in 13 patients using multiple
2.4-millimeter cryoprobes. Using only local anesthesia with mild sedation,
ultrasound guidance alone was used in six patients; seven patients required both
CT and ultrasound to better define ice margins. MR and/or clinical follow-up
were available for up to 65 months after cryotherapy.
SOURCE: Presented at the Society of Interventional Radiology Annual
Scientific Meeting in Tampa, FL, March 16, 2010