The value of APT weighted imaging in differentiating breast cancer patients with HER2 zero-, low- and over-expressing

Motivation: Breast cancer (BC) with low HER2 expression (HER2-low) may benefit from newly developed antibody-drug couplings, but identification of HER2-low by non-invasive imaging methods remains challenge. Goal(s): To assess whether DWI and amide proton transfer weighted imaging (APTWI) can help distinguish HER2-low from HER2 zero- (HER2-zero) and over-expressions (HER2-oe) in BC. Approach: 56 HER2-oe, 78 HER2-low, and 39 HER2-zero BC patients were enrolled. ADC and MTRasym(3.5ppm) were compared between the three groups. The identification ability was assessed by ROC analysis. Results: MTRasym (3.5ppm) and ADC are effective predictors for diagnosing HER2 expression levels, exhibiting superior predictive performance when utilized in combination. Impact: APTWI could be used as non-invasive biomarker for identifying HER2-zero,HER2-low, and HER2-oe. The application of APTWI would be beneficial for guiding treatment selection and dynamically monitoring HER2 expressing level throughout the course of treatment for BC patients.