MRI/CT Imaging for Axillary Lymph Nodes: What a New Breast Cancer Study Reveals

Emerging research suggests the combination of magnetic resonance imaging (MRI) and computed tomography (CT) may significantly improve axillary lymph node staging in patients with breast cancer.

In a new study, published in the Journal of Cancer Research and Clinical Oncology, researchers compared the sensitivity of mammography, sonography, MRI ad CT for diagnosing malignant tumors in axillary lymph nodes. According to the study, 382 patients had conventional imaging (mammography and/or sonography) and 52.61 percent of those patients also had cross-sectional MRI and CT imaging,

The study authors said the combination of all four modalities resulted in a 68.89 percent sensitivity rate for tumor-infiltrated axillary lymph nodes. However, cross-sectional imaging with MRI and CT showed significantly higher sensitivity (63.83 percent) in comparison to a combination of mammography and sonography (36.11 percent).

“The combination of advancing MRI technology and CT staging, both focusing on axillary lymph nodes, could possibly improve sensitivity in the future,” wrote Catharina Bartmann, M.D., who is affiliated with the Department of Obstetrics and Gynaecology at University Hospital in Wurzburg, Germany, and colleagues. “As CT examinations of the chest and the abdomen are the standard staging procedure for (breast cancer) patients with high risk of metastasis formation, this imaging data is already available.”

The combination of sonography, MRI and CT yielded a 68.09 sensitivity rate and the combination of mammography with MRI and CT had a 65.91 sensitivity rate, according to the study. Comparing the sensitivity rates of each imaging modality, the researchers noted that CT had a 51.4 sensitivity rate for detecting positive lymph nodes in comparison to the sensitivity rates for MRI (41.51 percent), sonography (34.56 percent) and mammography (14.60 percent). However, Bartmann and colleagues pointed out that MRI provides the most optimal imaging for detecting tumors smaller than 2 cm.

In regard to study limitations, the researchers noted that the retrospective nature of the study prevented the use of complete imaging techniques for all of the patients in the study. Selection bias is another possible limitation, according to the study authors. Noting that MRI/CT imaging was primarily utilized in patients with additional risk factors, Bartmann and colleagues conceded a higher probability of axillary tumor infiltration on cross-sectional imaging in this subgroup.