Infraclinic lesions (impalpable) with the indication of surgical excision require the use of a precise guidance technique to ensure the success of the excizion and to reduce to a minimum the excision of normal breast tissue. Depending on the location of the lesion and the radiologist or the surgeon preferences, different locating methods can be used: tegumentary marking (drawing on the skin), dye injection or needle-hook systems (Harpoon).
Preoperative localization can be made by marking the skin above the lesion, the patient being placed on her back with the arm in 90° abduction. In order to avoid applying pressure, the depth at which the tumor is localized will be measured and mark its position on the skin. The method is useful, in particular, in the case of medium size superficial lesions, when the distance between the injury and the skin is less than 2 cm.Tegumentary marking may be associated with the perilesional injection of a dye.
Preoperative localization can be performed with various metallic needle- hook (hooks) systems.
The eco-guided placing of such a mark does not require, in general, local anesthesia. To insert a needle- hook system the shortest path up to the lesion will be used, using a longitudinal approach technique. The needle is inserted through the lesion so that the distance between its tip and the edge of the lesion is less than 5 mm, after which the needle is removed and the metallic wire remains in place. The proximal end of the hook is attached to the skin and two orthogonal mammograms are performed. Mammography is useful for checking the spatial orientation between the lesion and the hook. This maneuver constitutes a forensic challenge for the radiologist.
After surgery, to verify the accuracy of the excision, the surgeon will compare the two mammograms with the radiography.
When using metal hooks, complications are rare. Cases can occur where the hook migrates (sometimes extra-mammary) or is cut during surgery.
The use of mammography exam as a screening method in detecting early breast cancer has as a consequence the discovery of a growing number of breast lesions, which requires conducting interventional image-guided maneuvers, either for the lesional diagnosis or for the preoperative localization.
If the lesion can be seen with both ultrasound and mammography, ultrasound guidance technique is preferred.
Accurate diagnosis of breast cancer increases considerably if percutaneous puncture results are correlated with clinical and imaging examination. Percutaneous interventional techniques requires close collaboration between radiologist, pathologist and surgeon, cooperation between these three specialties ensure optimal results.