Breast markers are tiny objects placed within breast tissue after a biopsy. They precisely identify the tissue removal site, serving as a reference for future imaging, follow-up, or potential surgery.
Core Components and Materials
Breast markers are metallic, primarily titanium, stainless steel, or nitinol. Titanium markers are often smaller than a sesame seed. 316LVM stainless steel is also common. Nitinol, a nickel-titanium alloy, is another.
Some markers also incorporate non-metallic elements. These include bioabsorbable carriers like collagen or polymers (e.g., polyglycolic acid pads or hydrogels). They assist in initial placement and stability, with some degrading over time while leaving the metallic marker.
Why Specific Materials Are Chosen
Materials for breast markers are chosen for properties suitable for human implantation. Biocompatibility is a primary consideration, ensuring no adverse reactions or toxicity. Titanium, for instance, is highly biocompatible and rarely triggers immune or allergic responses. Stainless steel is also inert in biological environments.
Durability and stability are also important, ensuring the marker remains intact and in place. Nitinol, for example, has shape-memory and superelastic properties, allowing compression for needle deployment and expansion to anchor it in tissue, minimizing movement. Visibility under various medical imaging techniques is another crucial aspect.
How Markers Interact with Imaging
Marker materials are chosen for visibility across various medical imaging modalities. On mammograms, their metallic composition makes them clearly visible, allowing radiologists to track the biopsy site in subsequent screenings. Markers are also visible during ultrasound, with some components enhancing their visibility.
MRI compatibility is important, as some metals interfere with scans. Most modern markers are MRI-compatible, often using non-ferromagnetic materials like titanium or specific stainless steel. While generally safe for MRI, they may create a small signal void or artifact on images. This artifact is typically small, usually not hindering diagnostic quality, and can even aid in localization.
Permanence and Safety
Breast markers remain permanently within breast tissue. Once placed, these tiny markers are typically not felt due to their small size and deep location. If biopsy results are benign, the marker stays in place, providing a long-term record for future imaging comparison. If surgery is required, the marker guides the surgeon to the precise area and is removed with the tissue.
Materials like titanium and medical-grade stainless steel are safe for long-term implantation due to their inert, biocompatible properties. Studies indicate breast marker placement is safe with minimal risks. Allergic reactions are rare, but individuals with known metal sensitivities (e.g., to nickel or titanium) should inform their provider, as non-metallic or alternative options exist. The body typically encapsulates the marker with a thin tissue layer, integrating it without significant reaction.