Unveiling Tissue Marker Migration in MRI-Guided Vacuum-Assisted Biopsies: Frequency, Factors, and Implications

Abstract

Purpose To evaluate the frequency and factors associated with clip migration in MRI-guided breast biopsies. Methods and materials We retrospectively evaluated all MRI-guided biopsies performed between January 2013 and December 2020 in our institution for clip migration. Only patients with follow-up breast MRI showing the clip were included in the study. Migration was defined as > 1 cm movement from the target lesion. Migration frequency and directions were recorded. Different factors associated with clip migration were analyzed using statistical tests as appropriate. Results A total of 291 biopsies in 268 women were included in the study with 31 migration events recorded (11%, 95%CI 7–15). All migrations occurred along the biopsy tract, 30 of them distal from the tip of the needle (97%). More than 50% regional fat (around the target lesion) was the strongest factor associated with migration, seen in 21/140 (15%), compared to 10/150 (7%) with less than 50% local fat (P = 0.023). Global fatty breast was more loosely associated with migration, showing borderline significance (P = 0.06). Other factors did not correlate with clip migration, including lesion size, depth or location, pathology result, breast thickness or biopsy approach. Conclusion Although clip migration following breast MRI-guided biopsy is an uncommon event, it occurs more often when the target lesion is surrounded by fat, with the clip usually displaced away from the biopsy needle. This information could be valuable for pre-surgical localization and surgical planning.