Prior to the commencement of the SCB it is important that a full explanation is given to the client including a description of any likely risks associated with the procedure; these may include bleeding, haematoma and pain. All staff in attendance should be introduced to the client and consent for the procedure should be gained. Informed consent is required for any procedure, but written consent is not essential for image guided core biopsy within the UK. Policies regarding obtaining written consent for breast interventional procedures are produced locally in accordance with hospital policy [9]. Obtaining medical history and other contraindications, for example anticoagulation, is essential prior to carrying out the procedure [10].

Prior to the commencement of an SCB a full discussion is undertaken between practitioners, regarding the position of the client, to facilitate the most effective plane of approach. The approach should enable the practitioner to easily position the client and facilitate accurate lesion targeting within the parameters of the stereotactic device. Appropriate positioning should ensure the shortest distance to the lesion is achieved by the biopsy needle. In general most stereotactic units require a minimum amount of tissue beneath the lesion to accommodate the firing mechanism of the biopsy device and prevent damage to the image receptor. If the breast thickness is found to be insufficient for SCB to be undertaken, methods to increase the thickness of the breast can be carefully attempted. This is usually undertaken by the addition of a spacer bar or platform sited between the breast and the support plate artificially increasing the breast thickness. Alternatively the procedure may be performed via the horizontal approach [11]. This is achieved with the addition of a lateral arm to the stereo unit.

Appropriate client positioning prior to biopsy is determined by the position of the lesion within the breast. In an upright stereo device clients with lesions within the upper half of the breast should be positioned in the cranio caudal position. Lesions in the lower inner quadrant are positioned medio-laterally and lesions identified in the lower outer quadrant positioned latero-medially. An illustration of this is can be visualised in the diagram above (Fig. 33.2).

Following client positioning a scout image is taken. This will aid positioning of the lesion within the digital window and provide a visual reference throughout the procedure; the stereo pair is then acquired. The X-ray tube is moved in the horizontal plane to different positions either side of the vertical axis, this generates two images forming the stereo pair. In most cases the fixed angulation is ±15° [2], and is determined by the manufacturer. The combination of the degree of tube angulation and the position of the lesion within the breast will influence the degree of shift seen in the resultant stereo pair. It is important that the practitioner is familiar with this concept therefore it is advisable to study the characteristics associated with lesion shift by practice with a dedicated biopsy phantom.

Once the appropriate stereotactic images have been acquired biopsy targets are set. The rationale for targeting small lesions, areas of distortion and clusters of calcification may differ from unit to unit and will usually be defined within local protocols. Following targeting the skin is prepared and local anaesthesia administered. Again the choice of anaesthesia is decided locally but in many units a local anaesthesia combined with adrenaline is used. The addition of adrenaline acts locally as a vasoconstrictor reducing bleeding and systemic absorption. The lasting action of the anaesthetic is also prolonged with the addition of adrenaline.

Prior to the insertion of the biopsy needle a small cut is made into the skin allowing access for the biopsy needle and minimise the possibility of skin tearing.

Currently there are a number of spring loaded automated core biopsy devices available for purchase. These comprise of either a fully or part disposable system available in a range of needle lengths, 10–16 cm and gauges 14–18, 14 gauge being the most commonly used in stereotactic biopsy.

For the majority of lesions the choice of a 10 cm biopsy needle is adequate (Fig. 33.3). However when a large compressed thicknesses is achieved and the lesion appears to be deep within the breast it is advisable to use a 13 cm needle to reach the lesion [12].

It is usual for between 5 and 10 core samples to be taken. The exact number of samples retrieved will be guided by local sampling regimes, the type of lesion to be sampled, and in some cases client compliance.

The optimum number of samples required to achieve a reliable histological diagnosis varies, with fewer samples required for mass lesions than areas of microcalcification [9]. For adequate sampling of microcalcification an optimum of either three or more cores containing calcium or five or more flecks of calcium in total should be retrieved [13]. As such, specimen imaging of the core samples is essential to demonstrate the removal of a representative sample of calcification [13]. During specimen imaging the breast should remain in compression because if further sampling is required then the procedure can immediately recommence.

Once the required number of samples has been obtained a gel based marker may be placed into the biopsy site. Studies have shown the placement of gel based markers following SCB can facilitate post operative ultrasound localisation at a later date [14]; they can also assist the multidisciplinary team discussion in cases of non-concordant results. The placement of gel based markers following biopsy may be routine practice in many units however the decision to deploy markers varies and may often be directed by a ‘marker placement protocol’ outlining to the practitioner the situations where a marker may be deployed.

Following the procedure the application of a constant amount of pressure to the wound site for approximately 5 minutes is advised. This will achieve haemostasis and minimise the risk of haematoma formation. When bleeding has ceased a simple pressure dressing should be placed to cover the wound. The client should be issued with appropriate after care instructions including a follow-up appointment to obtain results of the biopsy.

The development of VAB in the late 1990s provided an invaluable addition to achieving accurate pre-operative diagnosis. VAB rapidly overcame the limitations of SCB particularly in diagnosing small lesions and areas of microcalcification where under sampling may have underestimated disease [15].

Currently, The UK National Institute for Clinical Health and Care Excellence (NICE) and the UK National Health Breast Screening Programme (NHSBSP) have validated the use of VAB in both the diagnostic and therapeutic setting. The indications for use of VAB include:

There are many examples in the literature outlining the benefits for VAB, highlighting its association with increased rates of calcium retrieval and lower rates of under diagnosis in both in-situ and invasive disease [8].

Currently there are four VAB systems available commercially. Three of these comprise of a single entry operating system while the fourth, Vacora ® (BARD®), utilises a multiple entry approach. Two examples of the single entry systems (i.e. the ATEC® (HOLOGIC®) and the EnCore Enspire® (BARD®)) are represented in Figs. 33.4 and 33.5, the third being Mammotome®, Breast Care, Ethicon Endo-Surgery®. A comprehensive comparative review of all four VAB systems has been undertaken by Wilson et al. (2009) and is recommended reading for the practitioner [16].

VAB can be incorporated with both upright and prone stereotactic systems with initial imaging and client positioning being similar to that undertaken prior to SCB. It requires a single insertion of the biopsy probe and thereafter contiguous samples of tissue are acquired with vacuum assistance. VAB incorporates the use of a range of probes from 7 to 12 gauge, the larger gauge probes being mostly used for therapeutic excisions. Suction is applied to the sampling chamber to draw in the lesion to be sampled. The integrated rotating cutter advances across the sampling chamber separating the breast tissue. The resultant specimen is then transported into the specimen collection area. The VAB also has the facility to wash out the biopsy site via an integrated saline flush, this aims to reduce and evacuate any haematoma formation.