PEM scanners may reduce unnecessary breast
biopsies
23 Nov 2010
Positron Emission Mammography (PEM) may reduce unnecessary
breast biopsies, according to a multi-site study published in the
journal Radiology.
The study found that PEM was significantly more precise at
identifying benign and cancerous lesions, in what scientists call
positive predictive value or PPV, therefore reducing the number of
unnecessary biopsies. A common physician complaint regarding the use
of breast MRI is its tendency to identify suspicious lesions,
requiring biopsies, which ultimately are found to be benign.
This finding is a welcome outcome for women and physicians
looking for ways to reduce the patient trauma associated with
biopsies and for payors looking to reduce the costs associated with
unnecessary procedures.
The 388-woman study showed that PEM not only demonstrated a 6%
improvement in specificity at comparably high sensitivity, but that
PEM also had 31 fewer unnecessary biopsies and 26% higher PPV than
Breast MR. These results are also particularly significant for those
women who cannot tolerate an MR exam and require an alternate
imaging tool.
"The results of this study mean that not only do physicians have
an additional, powerful tool to help treat breast cancer but that
PEM is a legitimate and better alternative for the 16% of women who
cannot tolerate MR due to claustrophobia, metallic implants, body
habitus, or gadolinium reaction," said Wendie Berg, MD, PhD and
Principal Investigator for the trial.
Berg recently published an article in the January 2010 issue in
the journal Radiology examining the reasons why high-risk
women who were recommended for a MR breast screening test refused to
take the exam.
PEM scanners are high-resolution breast PET systems that can show
the location as well as the metabolic phase of a lesion. This
information is critical in determining whether a lesion is malignant
and influences the course of treatment. Other imaging systems, such
as mammography and ultrasound, show only the location, not the
metabolic phase. PEM scanners, which are about the size of an
ultrasound system, are manufactured by Naviscan, Inc. and have been
commercially available since 2007.
The NIH-sponsored multi-site study (NIH Grant 5R44CA103102)
examined women with newly-diagnosed breast cancer. Patients were
accrued from six leading clinical centers across the US: ARS Johns
Hopkins Green Spring, Boca Raton Community Hospital, Scripps
Clinic-Scripps Green Hospital, University of North Carolina,
University of Southern California Norris Cancer Center, and Anne
Arundel Medical Center.