Stereotactic procedures | Importance of biopsy for breast cancer diagnostics

Stereotactic procedures

The term stereotactic (stereo = spatial, taxis = order or orientation) is used to describe various techniques that involve working under X-ray control. By taking several images from different directions, the physician can orientate himself spatially when performing the biopsy and locate the findings precisely. Stereotactic procedures are mostly used for the biopsy of findings that can only be seen in mammography, e.g. conspicuous microcalcifications in the breast.

The various techniques then differ essentially only in the needle used and the amount of tissue sample taken. In the meantime, digital mammography is mostly used for X-ray control. In contrast to conventional mammography, the images are immediately available and the duration of the examination is thus greatly reduced.

Stereotactic punch biopsy and fine needle puncture

Both procedures are the same as described above, with the difference that the ultrasound is replaced by a mammography device. Taking the biopsy is somewhat more uncomfortable, as the patient has to sit still for a longer period of time while the breast is compressed in the mammography device for the scan. In addition, there is the radiation exposure caused by several images, which are necessary to localize the findings in three-dimensional space. Even with stereotactic punch biopsy/fine needle puncture, the reliability of the results is very high when the findings are taken. However, only few clinics have the technical possibilities for stereotactic punch biopsy.

Vacuum biopsy (MIBB = minimally invasive breast biopsy)

Vacuum biopsy (MIBB = minimally invasive breast biopsy) is a further development of conventional minimally invasive needle biopsies. Another name for this method is mammotome vacuum biopsy. It is used when mammography reveals altered tissue of five millimetres or more in size.

Vacuum biopsy can be combined with both imaging techniques, mammography and ultrasound. The combination with mammography is more common, which is why it is considered a stereotactic procedure. During the extraction, the patient usually lies on her stomach on a special examination table with an opening in which the breast is placed so that it cannot move or slip away during the examination.

A hollow needle about three millimetres in diameter is used for the vacuum biopsy. After a local anaesthetic, the hollow needle is inserted into the breast through a 3-4 mm long incision. Negative pressure (vacuum) is used to suck tissue into the hollow needle, which contains a tiny high-speed knife that separates the sucked-in sample from the rest of the tissue.

The tissue is then transported into an opening in the middle of the needle, from which it can be removed with forceps. The needle can rotate on its own axis during the tissue removal, so that samples can be taken from several locations of the findings and the surrounding area. This increases the reliability of the diagnosis. Some clinics have special devices in which the vacuum biopsy can also be performed while sitting. In addition, this technique can be used to insert a microclip after the samples have been taken, which marks the site of sample collection for later control examinations or operations.