Low-Dose Positron Emission Mammography Shows Promise in Breast Cancer Detection

In a groundbreaking prospective study approved by the research ethics board, scientists have explored the feasibility of utilizing low-dose positron emission mammography (PEM) concurrently with magnetic resonance imaging (MRI) to identify breast cancer and assess its local extent.

The trial results were published in the journal Radiology: Imaging Cancer.

The early detection of breast cancer is crucial for improving overall survival rates. While mammography is the primary imaging modality, challenges persist in detecting nonpalpable lesions, especially in patients with dense breast tissue. Advances in modalities like MRI, contrast-enhanced mammography, and molecular breast imaging (MBI) show promise in overcoming these limitations. This study explores the feasibility of low-dose positron emission mammography (PEM) alongside MRI for effective breast cancer identification and localization.

The research, conducted with newly diagnosed breast cancer patients undergoing concurrent breast MRI acquisitions, included participants independent of breast density, tumor size, and histopathologic cancer subtype. Low-dose PEM, utilizing up to 185 MBq of fluorine 18–labeled fluorodeoxyglucose (18F-FDG), was administered. PEM images acquired 1- and 4 hours post-injection, were reviewed by two breast radiologists unaware of cancer locations. The findings were then correlated with histopathologic results. Logistic regression and summary statistics were employed for detection accuracy and participant details, and a comparative analysis with MRI assessed the efficacy of PEM in detecting additional lesions.

Results:

The cohort consisted of 25 female participants with a median age of 52 years.

Remarkably, low-dose PEM identified 96% (24 out of 25) of cancers, including 19 invasive cancers and five in situ diseases, from 100 sets of bilateral images.

This performance was maintained even after 3 hours of radiotracer uptake.

The median size of invasive cancers detected was 31 mm, ranging from 10 to 120 mm.

Notably, three additional in situ grade 2 lesions were missed at PEM, though the study did not find a statistically significant difference.

False-positive additional lesions were less frequent with PEM compared to MRI (16% vs. 62%; P = .14), highlighting the potential of PEM in minimizing false-positive results.

The study presents compelling evidence supporting the feasibility of a low-dose PEM system in the detection of invasive breast cancer. While acknowledging the need for large-scale clinical trials to validate these initial findings, this research underscores the promising role of low-dose PEM as an imaging tool in the diagnosis of breast cancer. The potential implications of this innovative approach could significantly contribute to enhancing accuracy and reducing false positives in breast cancer detection, ultimately improving patient outcomes.

Further reading: Freitas V, Li X, Scaranelo A, et al. Breast Cancer Detection Using a Low-Dose Positron Emission Digital Mammography System. Radiol Imaging Cancer. 2024;6(2):e230020. doi:10.1148/rycan.230020