RESUMO
OBJECTIVE: To determine whether the type of projection used-same as or orthogonal to the projection used during a stereotactic-guided core needle biopsy procedure-to obtain the first view on a 2-view postbiopsy mammogram affects biopsy marker clip migration. PATIENTS AND METHODS: We prospectively recruited women scheduled to undergo stereotactic-guided core needle breast biopsy with marker clip deployment and categorized the women randomly into one of the following 2 groups: first view on the postbiopsy mammogram obtained in the same projection as that used during the biopsy procedure (group 1), or first view on the postbiopsy mammogram obtained orthogonally to the projection used during the biopsy procedure (group 2). Masks of the prebiopsy and postbiopsy mammograms were used to determine whether and how far the biopsy marker clip moved from the biopsy cavity. RESULTS: Sixty-two biopsies were performed in 60 patients (mean age = 56 years; range: 30-78 years); 30 women (32 lesions) were randomized to group 1 and 30 women (30 lesions) were randomized to group 2. Marker clip migration occurred in 10 cases in group 1 (20%, <1cm; 30%, 1-3cm; and 60%, >3cm) and 8 cases in group 2 (0%, <1cm; 75%, 1-3cm; and 25%, >3cm). The mean displacement distance was 0.84cm in group 1 and 0.67cm in group 2 (P = 0.83). The mean displacement distance difference was -0.17cm with a 95% bootstrap confidence interval from -0.87 to 0.57cm. CONCLUSION: The type of projection used to obtain the first view on the postbiopsy mammogram, relative to that used during the stereotactic biopsy procedure, did not affect biopsy marker clip migration.