Long-term Migration of Breast Biopsy Markers with and without Mitigating Strategies in an Animal Model

In the care of patients with breast cancer, it is now common for a radiologist to place biopsy markers in suspicious axillary lymph nodes that are biopsied so that the lymph nodes can be identified for later surgical excision. Migration of markers has been reported, but has only been sparingly evaluated. The objective of this study was to evaluate the migration of biopsy markers in a porcine model using longitudinal X-ray computed tomography (CT) imaging MATERIALS AND METHODS: We report the evaluation of migration of a commercial biopsy marker (Tumark Professional Q) and a marker made of polymethyl methacrylate (PMMA) that is being developed for improved ultrasound imaging detection. We tested these markers alone as well as combined with adjacent hernia mesh and injections of ethanol to promote local inflammatory responses to mitigate migration. We imaged animals (N = 3) at monthly time points with CT to evaluate marker-to-lymph node spatial relationships.

We observed that migration was the largest with the PMMA marker (< 10 mm) and was mitigated with the mesh and ethanol perturbations. Histomorphometry analysis of the markers revealed that a rind around the markers was formed and increased with the inclusion of mesh and ethanol.

This pilot study demonstrated that marker migration could be characterized over time and different perturbations modified the amount of migration. Future studies should incorporate randomization of marker placement and larger animal cohorts.