Usual mammography often fails in women who have dense breast tissue. According to Eric Rosen, M.D., a Duke University Medical Center physician and lead author on the study, "In women with dense breasts, it's very hard to pick out even large anatomic abnormalities."
Stan Majewski, Jefferson Lab Detector Group Leader and principal investigator on the instrumentation part of the project, led the team that designed and built the PEM unit. It reveals breast tissue that is showing higher metabolism than other areas. "The imager we built is a functional imager. That is, it indicates something about physiology, which can be different from anatomy," he says.
In this imaging procedure, a small dose of radioactive molecules that look like sugar, called fluorodeoxyglucose (FDG), are injected into the body, where they're absorbed by cancerous tumours. "By detecting areas that have increased glucose metabolism, you can often distinguish a cancer between normal surrounding tissue, which in general has low uptake of FDG," Dr. Rosen says.
For the study, Duke physicians recruited patients with suspicious mammograms who were scheduled for biopsies. "We recruited 23 patients that had 23 lesions that were highly suggestive of malignancy. PEM showed 20 lesions, 20 abnormalities, of which 18 were cancer and two were not cancer," Dr. Rosen says.
The PEM unit missed three tumours, all of which were located very close to the chest wall, an area that PEM doesn't image well. And of the 20 lesions spotted by the PEM system, one was not picked up by mammography. A subsequent biopsy revealed that this additional lesion was cancerous.
Dr. Rosen says the study was indeed a success. "What we concluded is that our PEM unit is capable of detecting cancer, it's capable of demonstrating small breast malignancies, and that it can be performed in the breast clinic with a small dose of FDG and a very short, 5-minute acquisition time", he adds.
MEDICA.de; Source: Duke University Medical Center