Magnetic resonance imaging of the breast in evaluating residual diseases at lumpectomy site soon after excisional biopsy.

OBJECTIVE: To evaluate the role of magnetic resonance imaging (MRI) in the detection of residual disease for patients after excisional biopsy of breast carcinoma, before re-excision.

MATERIALS AND METHODS: We performed a retrospective review of 97 patients who underwent MRI soon after excisional biopsy of breast carcinoma with undeterminable margin status before further surgical intervention to determine the value of MRI in detecting residual disease.

RESULTS: The positive predictive value was 50.0%. The negative predictive value was 78.9%. The MRI detected 54.5% of the residual disease for invasive ductal carcinoma and 100% for ductal carcinoma in situ. Positive predictive value and sensitivity for MRI conducted within 14 days of the original surgery were lower than those for MRI conducted after 14 days of the original surgery, being 31.6% and 46.2% versus 66.7% and 73.4%, respectively. The difference between the positive predictive value within 14 days versus after 14 days was statistically significant.

CONCLUSION: Magnetic resonance imaging in detecting residual disease soon after excisional biopsy for breast carcinoma had a low positive predictive value and moderately high negative predictive value. Magnetic resonance imaging was more sensitive in detecting residual ductal carcinoma in situ than invasive ductal carcinoma. Magnetic resonance imaging conducted more than 14 days after the original biopsy had a significantly higher positive predictive value than MRI done within 14 days.