Outcome analysis of 9-gauge MRI-guided vacuum-assisted core needle breast biopsies

Abstract

Objective: The purpose of this article is to correlate 9-gauge MRI-guided vacuum-assisted breast biopsy with surgical histologic findings to determine the upgrade rate and to correlate the frequency of MRI-guided vacuum-assisted breast biopsy cancer diagnosis with breast MRI indications and enhancement characteristics of targeted lesions.

Materials and methods: A database search was performed of all MRI-guided vacuum-assisted breast biopsies performed from January 1, 2005, to September 31, 2010. The breast MRI indications, history, age, risk factors, lesion size, enhancement characteristics, and pathologic diagnoses at MRI-guided vacuum-assisted breast biopsy and at surgery were documented. Fisher exact test and analysis of variance were used for statistical analysis.

Results: A total of 218 lesions underwent MRI-guided vacuum-assisted breast biopsy in 197 women (mean age, 52 years; range, 28-76 years), of which 85 (39%) had surgical correlation. Of the 218 lesions, 48 (22%) were malignant, 133 (61%) were benign, and 37 (17%) were high risk according to MRI-guided vacuum-assisted breast biopsy. Ten of 85 lesions (12%) were upgraded to malignancy at surgery, with a final malignancy rate of 25%. The frequency of malignancy was significantly higher in patients presenting for diagnostic (50/177 [28%]) versus screening (4/41 [10%]; p < 0.05) evaluation, patients with ipsilateral cancer (22/49 [45%]; p < 0.001), and lesions with washout kinetics (34/103 [33%]; p < 0.05) and was relatively higher in lesions with nonmasslike enhancement (26/76 [34%]; p = 0.07), which represented ductal carcinoma in situ in the majority of cases (17/26 [65%]; p < 0.005).

Conclusion: Patients with ipsilateral cancer who have additional suspicious lesions identified on MRI require careful evaluation and biopsy to exclude additional sites of cancer that may impact surgical management.

Fig. 1

58-year-old woman with isolated Paget's disease in the left nipple and no mammographic or sonographic abnormality. A. Sagittal T1 weighted fat suppressed 3D fast spoiled gradient-echo subtraction MR image with post processed parametric color map demonstrates non-mass-like enhancement (arrow). B. Kinetic display shows washout enhancement kinetic pattern. C. Axial T1 weighted fat suppressed 3D fast spoiled gradient-echo image demonstrates non-mass-like regional clumped enhancement (arrow). D. Axial T1 weighted fat suppressed fast relaxation fast spin echo image obtained during biopsy shows obturator in place (arrow). Histopathology at MRVAB and surgery was ductal carcinoma in situ, Grade 3.

Fig. 2

66-year-old woman with right breast cancer presents for staging MRI, which reveals abnormal enhancement in the contralateral left breast. A. Left sagittal T1 weighted fat suppressed 3D fast spoiled gradient-echo subtraction MR image with post processed parametric color map demonstrates non-mass-like enhancement (arrow). B. Kinetic display shows plateau enhancement kinetics. C. Axial T1 weighted fat suppressed 3D fast spoiled gradient-echo image demonstrates non-mass-like regional clumped enhancement (arrow). D. Axial T1 weighted fat suppressed fast relaxation fast spin echo image obtained during biopsy shows obturator in place (arrow). Histopathology at MRVAB was fibroadenoma.

Fig. 3

69-year-old woman with palpable thickening at 12 o’clock and negative mammogram and sonography. A. Sagittal T1 weighted fat suppressed 3D fast spoiled gradient-echo subtraction MR image with post processed parametric color map demonstrates non-mass-like regional enhancement (arrow). B. Kinetic display shows washout enhancement kinetics. C. Axial T1 weighted fat suppressed 3D fast spoiled gradient-echo image demonstrates non-mass-like regional enhancement (arrow). D. Axial T1 weighted fat suppressed fast relaxation fast spin echo image obtained during biopsy shows obturator in place (arrow). Histopathology at MRVAB was atypical ductal hyperplasia. Final histopathology at surgical excision was ductal carcinoma in situ, Grade 2.