Patient outcomes in canceled MRI-guided breast biopsies.

OBJECTIVE: The reported frequency of aborted MRI-guided breast biopsies ranges from 8% to 17%, usually secondary to nonvisualization at attempted biopsy. Our study examines the frequency of MRI-guided breast biopsies aborted because of lesion nonvisualization and the subsequent risk of malignancy.

MATERIALS AND METHODS: We identified 350 patients and 445 lesions scheduled for MRI-guided biopsy between January 1, 2007, and December 31, 2009. Medical records and imaging studies were reviewed to ascertain patient demographics, lesion and imaging characteristics, and subsequent pathology results. Chi-square statistics were calculated for patient level analyses.

RESULTS: MRI-guided biopsies were aborted in 13% (56/445) of lesions and 15% (53/350; 95% CI, 11.6-19.3%) of patients because of nonvisualization of the biopsy target at the time of attempted biopsy. Of these 53 patients, 50 patients had follow-up data available. Malignancy was subsequently diagnosed in five of those 50 patients (10%; 95% CI, 3.3-21.8%), three with invasive ductal carcinomas and two with ductal carcinoma in situ. The mean time to malignant diagnosis from the date of aborted biopsy was 2.6 months (range, 1.1-6.9 months).

CONCLUSION: Informed consent for MRI-guided breast biopsies should include discussion of biopsy cancellation because of nonvisualization of the target lesion. The low yet significant risk of malignancy in patients subsequent to an aborted MRI-guided breast biopsy warrants short-term follow-up MRI after a canceled biopsy.