The Future of Positron Emission Mammography (PEM)

Objectives Positron Emission Mammography (PEM) has been introduced as a diagnostic tool to aid the conventional imaging technique of mammography for detecting lesions in women with breast cancer. This high resolution imaging technique utilizes an intravenous injection of 18F-FDG as an effective imaging agent in patients with dense breast tissue that may present as multiple lesions. The purpose of this study is to evaluate the advantages of utilizing PEM as a specialized diagnostic asset, and to determine the drawbacks associated with this new imaging procedure.

Methods Multiple clinical case studies were reviewed to assess the usefulness of PEM in patients with established breast cancer. The sensitivity of PEM was evaluated as a supplementary component to mammography and for use with patients contraindicated for MRI.

Results PEM presents a stronger advantage in the ability to identify small hypermetabolic lesions in denser breast tissue that may have been undetected by conventional mammography. PEM can distinguish lesions measuring <2 cm due to its higher spatial resolution. The imaging sensitivity of PEM has been reported as 60% to 70% even with extremely small tumors that are measuring <1 cm in dimension. When PEM has been directly compared to other tumor imaging techniques such as MRI, the stated sensitivity of PEM was 93% for identified lesions and 85% for unanticipated ancillary lesions that mimics the sensitivity of MRI for this same indication. While PEM produces a higher radiation exposure to noncancerous areas, it is still practical for detection in patients that are contraindicated for MRI.

Conclusions Currently, PEM is being employed as a complementary imaging asset in patients with a history of breast cancer that had detectable abnormalities in their mammogram. Usually, these patients are contemplating breast conservation surgery as an optional assessment of multifocal disease within their dense breast tissue. PEM’s future in diagnostic imaging is proving to be a helpful tool in the evolution of breast imaging, and despite the drawbacks, it is effectively paving the way for more advancements in detection of breast cancer in patients.