Feasibility of Contrast-Enhanced Spectral Mammography in Japan: A Pilot Study

Contrast-enhanced spectral mammography (CESM) provides diagnostic capability comparable to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI); however, in Japan, CESM is not routinely performed because the use of iodinated contrast agents for CESM is not approved. Evidence on CESM from Japan is therefore scarce. This study assessed the feasibility, diagnostic performance, and patient experience of CESM in Japanese patients with breast cancer.

This study enrolled women aged 20-80 years with histologically confirmed breast cancer who were scheduled for surgery. CESM and DCE-MRI were performed within two months preoperatively. Images were independently interpreted by a breast radiologist. Tumor size, Breast Imaging Report and Data System (BI-RADS) category, and breast density were assessed and compared with postoperative pathology. Average glandular dose (AGD) and contrast-related reactions were evaluated. Patients answered questions regarding examination time, comfort, positioning, and preferred modality. Pearson correlation coefficients were calculated to assess the relationship among tumor sizes measured on CESM, DCE-MRI, and pathology.

A total of nine patients (11 malignant lesions) were analyzed. CESM detected 10 lesions (detection rate 90.9%) and DCE-MRI detected all lesions (100%). Tumor size measured by CESM (r = 0.95) and DCE-MRI (r = 0.94) showed strong correlation with pathology. AGD averaged 3.1 mGy, and no allergic reactions occurred. Patients preferred CESM primarily due to shorter examination time, while noise and long duration were the main disadvantages of DCE-MRI.

CESM demonstrated high diagnostic performance that was comparable to DCE-MRI and superior to mammography, particularly for dense breasts. Considering its shorter examination time and favorable patient acceptance, CESM may serve as a valuable diagnostic option in Japan, thus warranting further clinical research.