Novel Imaging Technique Could Transform Breast Cancer Detection

By MedImaging International staff writers
Posted on 12 Feb 2024

Image: The Radialis PET Imager (Photo courtesy of RSNA)

Mammography, while effective in the early detection of breast cancer, has reduced sensitivity in dense breast tissue due to the masking effect of dense fibroglandular tissue. This presents a challenge, as nearly half the screening population has dense breasts, often necessitating additional imaging, like MRI, after mammography. Now, a new study has found that low-dose positron emission mammography (PEM) not only offers high sensitivity in detecting breast cancer but also significantly lowers the likelihood of false positive results. This innovative molecular imaging technique, which operates at a radiation dose similar to traditional mammography, could provide a more reliable breast cancer screening option for a wider patient demographic.

The study by researchers at the University of Toronto (Ontario, Canada) involved 25 women, with a median age of 52, who had been recently diagnosed with breast cancer. They underwent low-dose PEM using the radiotracer fluorine 18-labeled fluorodeoxyglucose (18F-FDG). Two breast radiologists assessed the PEM images taken one and four hours after the 18F-FDG injection and matched their findings with laboratory results. The research revealed that PEM's performance paralleled that of MRI, identifying 24 out of 25 invasive cancers (96%) with a notably lower false positive rate of only 16%, compared to MRI’s 62%. PEM's sensitivity and reduced rate of false positives could potentially reduce downstream healthcare costs by eliminating the need for further unnecessary procedures, unlike MRI. Furthermore, PEM offers a patient-friendly experience by delivering a radiation dose similar to mammography without requiring uncomfortable breast compression.

The potential clinical applications of low-dose PEM extend to both screening and diagnostic scenarios. It could be instrumental in clarifying ambiguous mammogram results, evaluating chemotherapy responses, and determining the disease's extent in newly diagnosed breast cancer, including the involvement of the opposite breast. The University of Toronto team is currently exploring PEM's ability to decrease the high rates of false positives often associated with MRI scans. If PEM proves effective in reducing these rates, it could significantly alleviate the emotional distress and anxiety associated with false positives and may lead to fewer unnecessary biopsies and treatments. Further research is necessary to precisely define low-dose PEM’s role and effectiveness in clinical settings.

"The integration of these features—high sensitivity, lower false-positive rates, cost-efficiency, acceptable radiation levels without compression, and independence from breast density—positions this emerging imaging modality as a potential groundbreaking advancement in the early detection of breast cancer," said study lead author Vivianne Freitas, M.D., M.Sc., assistant professor at the University of Toronto. "As such, it holds the promise of transforming breast cancer diagnostics and screening in the near future, complementing or even improving current imaging methods, marking a significant step forward in breast cancer care."

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University of Toronto