Contrast-enhanced digital mammography (CEDM) could make a significant impact on the diagnosis of breast lesions assigned a BI-RADS category of 4A or 4B, according to new research published in Academic Radiology.
“Contrast-enhanced MRI is currently the most sensitive test for breast cancer detection, primarily due to improved lesion conspicuity from the contrast enhancement,” wrote Margarita L. Zuley, MD, University of Pittsburgh Medical Center, and colleagues. “However, MRI suffers from relatively low specificity, is expensive and not always easily accessible. Thus, MRI is not ideal as a biopsy triage tool.”
Zuley et al. noted that CEDM has a similar sensitivity to MRI and wanted to assess its ability to assist with the diagnosis and treatment of patients with soft tissue breast lesions classified as BI-RADS 4A (low suspicion for malignancy) or BI-RADS 4B (moderate suspicion for malignancy). For the study, a team of eight radiologists independently reviewed 60 lesions from 54 patients between the ages of 34 and 74 years old. Lesions were interpreted and rated by each reader three times: once with digital mammography (DM) and digital breast tomosynthesis (DBT), once with ultrasound (US) images added and once with CEDM added.
While 49 lesions were benign, nine were pathology-confirmed cancers and the other two were high-risk lesions.
“The two high risk lesions in this cohort were a mass found to be an atypical papilloma at percutaneous biopsy and an area of architectural distortion found to be lobular carcinoma in situ at core biopsy,” the authors explained. “Both were surgically removed, and neither were upgraded to malignancy.”
Overall, BI-RADS assessments for DM/DBT and CEDM were “substantially more accurate” than for DM/DBT alone. The reader-averaged area under the ROC curve (AUC) was 0.85 after adding CEDM, 0.75 after adding US and 0.66 for DM/DBT alone.
“Similar patterns were observed for individual radiologists,” the authors wrote. “The AUCs estimated for each of the eight readers were the highest for CEDM and the lowest for DM/DBT.”
The addition of CEDM images also increased true positive rates and decreased false positive rates.
According to the researchers, these findings “suggest that CEDM use will likely translate into fewer biopsies in patients with benign lesions” in a clinical setting. CEDM could have other benefits to patients as well. For instance, CEDM implementation could lead to cost savings and improved patient satisfaction.
“If validated by larger trials, CEDM could significantly reduce the rate of biopsy of actually benign lesions without impacting cancer sensitivity and thus could increase the positive predictive value of biopsy,” the authors concluded. “Given that more than one million breast biopsies are performed annually in the United States alone, and that close to 90% of biopsies are performed for low to intermediate risk lesions, the potential impact in terms of number of women benefitting from biopsy avoidance and reduction in cost to society is high.”