The insertion of seeds is carried out through two different imaging techniques,
as follows.
Ultrasound-guided seed insertion
We use a Canon medical ultrasound,
model Aplio a450.
We emphasize that one of the advantages of Endomag needles is their high echogenicity,
which eases the visualization of the very needle,
as well as the ultrasound procedure itself.
Seed insertion guided by stereotaxy with mammography
We use a direct digital mammograph by Hologic® with its Affirm® stereotaxy system,
with which we carry out vacuum-guided stereotaxy.
Our team was the first in Spain to use the Affirm® system alongside Magseed® magnetic seeds for localizing non-palpable lesions. Fig. 6
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The affected breast is placed in the mammography unit's detector,
and using a compression plate with an aperture,
the area containing the lesion is localized,
with help from previous mammograms. Fig. 9
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Pressure is maintained on the needle with the guides and it is inserted manually until the coordinates in the viewer become X0,
Y0 and Z0,
which indicates that the point at which the seed is to be inserted has been reached. Fig. 14
Once the seed is inserted,
independent of the technique employed,
it is checked by mammography through lateral and craniocaudal projections. Fig. 17
The radiologist certifies that the seed is correctly inserted,
emits his report accordingly,
and the surgical team can procede to program the date for excision of the affected tissue. The mammographic confirmation of the specimen is performed on the day of surgery. Fig. 18
During the period studied (December 2017 - December 2018) we marked 36 patients with Magseed® magnetic seeds.
On two occasions the insertion of two markers was necessary.
25 patients had proceeded from the screening program while 12 came from the diagnostic mammography program.
Localized impalpable lesions were distributed as follows: 13 nodules,
9 assymetries,
3 distorsions,
9 microcalcifications and 2 neoadjuvancies Fig. 19.
The diagnosis of these lesions was made by ultrasound in 25 cases,
and by stereotaxy in 12 cases.
The magnetic marker was inserted in 32 cases through ultrasound and in 4 cases through stereotaxy.
Ultrasound was used in the greater number of cases for insertion of the magnetic marker because it was observed that after stereotaxy a small hematoma remained,
which was used as a reference to locate the impalpable lesion. Fig. 20