MRI Not Quite There for Lymph Node Diagnosis in Breast Cancer

Magnetic resonance imaging’s accuracy in detecting cancer in the lymph nodes of newly diagnosed breast cancer patients is nothing to sniff at – 80 percent with diffusion-weighted MRI and 85 percent with axial T1-weighted MRI, Canadian researchers have reported. But it’s not quite high enough to skip a lymph node dissection, according to a study published online Dec. 5 in the journal Radiology.

University of Toronto researchers chose 61 women (average age 53) with invasive breast cancer to undergo preoperative breast MRI. Axial T1-weighted MRI without fat saturation and diffusion-weighted (DW) MR images were analyzed by two experienced radiologists uninformed of the pathology findings.

They found the sensitivity, specificity, and accuracy to be 88 percent, 82 percent, and 85 percent, respectively, for axial T1-weighted MR imaging and 84 percent, 77 percent, and 80 percent for diffusion-weighted (DW) imaging. Apparent diffusion coefficients (ADCs) were significantly lower in the malignant group.

The team concluded that unenhanced MRI techniques showed high accuracy in the preoperative evaluation of patients with invasive breast cancer, and that, while the results indicated reliable and reproducible assessment with DW imaging, “it is unlikely to be useful in clinical practice.”