MRI Aids Detection of Residual Breast Cancer After Biopsy

Dynamic contrast-enhanced breast MRI aids physicians in predicting residual disease after an excisional biopsy for breast cancer has been performed, according to a study published in the American Journal of Roentgenology.

Researchers from South Korea undertook a study to assess the diagnostic performance of breast MRIs in evaluating if there remained any residual breast cancer in patients who had undergone an excisional biopsy. The researchers analyzed the MRI findings of 203 patients who, between January 2007 and December 2011, had:

• Undergone imaging of postoperative sites after excisional biopsy;
• Not undergone chemotherapy or radiotherapy before the MRI; and
• Underwent definitive surgery within 30 days after the MRI.

The enhancement patterns were classified into four categories: no enhancement (P1), thin regular rim enhancement (P2), thick or irregular rim enhancement (P3), and nodular or non-mass-like enhancement (P4) around the postoperative sites. The enhancement kinetics were assessed as persistent, plateau, and washout pattern.

The results showed that among the 207 breast MRI examinations of the 203 patients, 144 breasts showed signs of residual breast cancer at histopathologic examination after definitive surgery.

When the enhancements P1 and P2 were considered to be negative for residual cancer and P3 and P4 were considered positive, the sensitivity, specificity, positive and negative predictive values, and accuracy were 79.9 percent, 73.0 percent, 87.1 percent, 61.3 percent, and 77.8 percent, respectively.

The specificity and positive predictive value improved to 90.5 percent and 91.7 percent, when analyzed with washout enhancement kinetics as another positive finding for residual cancer.

“Although the overlapping features of the postsurgical changes and malignant lesions remain as the limitations, dynamic contrast-enhanced breast MRI is a useful tool for residual disease prediction after excisional biopsy for breast cancer,” the authors wrote. “Combined use of morphologic and kinetic evaluation parameters improved the diagnostic performance.”

The authors recommended that MRI not be unreasonably delayed after excisional biopsy considering the risk of prolonging definitive surgery.