Undergoing a breast biopsy can be a very stressful event for a patient. Typically the psychological stress is far more bothersome than the physical discomfort experienced during the procedure. Although we routinely offer premedication with anxiolytics for our stereotactic patients, premedication of our US patients is more variable. Music is routinely used in our procedure rooms or patients may bring in their own music/listening devices. Studies have shown both music and anxiolytics decrease procedure-related anxiety in breast biopsy patients [17]. 5–10 mg of valium or 0.25–0.5 mg of alprazolam are often used for outpatient procedures. Medications are given in the department approximately 30 min prior to the procedure and after informed consent has been obtained. We require all patients to have someone available to drive them home.

In our department patients usually undergo a prebiopsy consultation, ideally performed the same day as the diagnostic imaging that resulted in a biopsy recommendation. The aim is to discuss the biopsy, answer any questions, go over consents, address stress reduction techniques, etc. Patients are instructed to avoid aspirin and NSAIDs (such as ibuprofen) prior to biopsy. Patients referred from outside facilities may be consulted over the phone. When the patient arrives in the biopsy suite, the procedure is discussed in detail with the patient, if this has not been done ahead of time. Informed consent must be obtained from the patient. Risks, benefits, and alternatives should be discussed as well as a thorough discussion of what the patient should expect during the biopsy. Immediately prior to the procedure, a universal “time-out” is performed.

The patient is placed supine on the table, with the ipsilateral arm elevated above the head. The physician then scans to confirm lesion location and determine the best approach to use. If needed the patient may be repositioned to an oblique angle for better access to a lateral lesion. Needles will pass more easily through fatty and glandular tissue than dense echogenic fibrous tissue. As such, finding an approach path with fatty tissue rather than dense tissue is preferred when possible (Fig. 12.4a, b). Use of Doppler may be helpful to avoid vessels. The subareolar region should be avoided if possible as this tends to be a very tender and sometime challenging area to anesthetize. If the mass is located in the subareolar region, a “nipple block” may be performed with topical lidocaine (such as EMLA®, AstraZeneca) with an occlusive dressing, followed by intradermal injection of lidocaine circumferentially around the nipple-areolar complex [18].

As a general rule, the shortest distance from the skin to the lesion should be used, keeping in mind the basic principles of ultrasound guidance. Although a vertical approach may be the shortest distance, a more lateral or oblique approach is required for ultrasound visualization. The intensity of the echoes produced by the needle increases as the angle of incidence decreases, with the most useful specular reflections taking place when the ultrasound beam strikes the reflector at 90° to the surface of the needle. The needle must be parallel to the long axis of the transducer to produce the maximal number of reflected echoes for visualization. The needle should also be as parallel to the chest wall as possible (Fig. 12.5a–c).

Images should be obtained documenting lesion location, approach, and any pertinent findings (adjacent chest wall, skin, implant, etc.).

After choosing the best approach, the biopsy tray is assembled as per physician preference. The tray and supplies should be positioned to ensure maximum accessibility and ease of use (Fig. 12.6). When setting up the tray, one should always be cognizant of accidental needle sticks or contamination. Examining your equipment prior to use to ensure no defects is always good practice. Many radiologists perform a test firing of the biopsy device to confirm proper function. This also provides an opportunity to warn the patient of the sound to avoid a startle reaction during the actual procedure. It should be noted, however, that some device manuals specifically precaution “never test the product by firing into the air” [19]. The breast is prepped and draped in the normal sterile fashion. Betadine solution is used to cleanse the skin and a sterile drape is placed. The transducer is routinely cleansed or a sterile probe cover can be used. One percent lidocaine (with or without epinephrine 1:100,000) is used for local anesthesia. Use of lidocaine with epinephrine can decrease bleeding and subsequent bruising. We prefer to buffer our lidocaine to decrease the pain associated with dermal injection. Ten milliliters of 1 % lidocaine (with or without epinephrine) is diluted with 1 mL of 8.4 % sodium bicarbonate [20, 21]. A 30-G needle is used for the initial superficial injection which also significantly reduces discomfort, with most patients reporting minimal to no pain with injection. This is followed by deeper injection with a 25-G 1 ½ needle. Ultrasound guidance should be used while giving anesthesia as this gives the radiologist a feel for the angle and approach that will be needed for the actual biopsy, a sort of trial run. Additionally any distortion (fluid pockets or hemorrhage) caused by the lidocaine can be seen real time so as not to confuse the subsequent biopsy. The lidocaine syringe should be well flushed before use to avoid introduction of air into the target field, which could obscure lesion visualization. The lidocaine placement can also be used to “move” the lesion as necessary, such as elevating a deep lesion off the chest wall by injecting the lidocaine deep to the lesion and “pushing” it more superiorly. Alternatively it can be used to make a shallow lesion “deeper.”

A small skin nick is made with a #11 blade scalpel. Although targeting systems are available, the freehand method is preferred by most radiologists and is used at our institution. The physician holds the transducer in one hand (usually the nondominant hand) and the biopsy device in the other. Alternately, a well-trained technologist can hold the transducer allowing the physician to have both hands free for the biopsy. The skin entry point should be shallow, located 1–2 cm from the edge of the transducer to ensure a needle path that is parallel with the transducer (Figs. 12.7, 12.8a–e, 12.9a, b, and 12.10a, b). As such, the angle of incidence is zero, creating maximal specular reflection and allowing visualization of the entire needle and tip. Steep angles and short axis imaging can lead to inaccurate needle tip location and poor sampling.

The needle is inserted and advanced under the long axis of the transducer. The transducer hand should now be fixed and still. Your eyes should be in the habit of mostly looking at the breast, not the screen. With a “mental image” of where the mass is, the needle is moved to the transducer. Once in position, a prefire image is obtained for documentation. The needle should be positioned in or at the edge of the mass. Prefire positioning depends on several variables. First you must be aware of the penetration depth or “throw” of the needle. Most throws are ~2.2 cm, meaning the needle tip will be advanced 2.2 cm from the original prefire tip location. The length of the sample notch is ~1.9 cm. There is also a small ~6–7-mm dead space at the needle tip. It is important to be aware of the throw, dead space length, and notch size of whatever needle you are using (Fig. 12.11a, b). If sampling a large lesion, the prefire position may be just in front of the mass to sample both the edge (perilesional) and the center portion of the lesion (Fig. 12.12). Alternatively the tip can be placed within the lesion, especially if the mass moves and the needle “bounces off” the mass. In smaller lesions, the needle tip must be further away from the mass to ensure the mass lies within the sample notch postfire. Prior to firing the needle, one must estimate the postfire needle position to insure no unwanted structures are in the expected path.

Obtaining a rim of normal perilesional tissue can aid the pathologist in making the correct diagnosis. Multiple areas of the lesion should be sampled to decrease sampling error and improve diagnosis (Fig. 12.13a, b). Another key point to remember is to use the spring to your advantage. Some lesions tend to be “pushed away” from the needle as it is advanced. The rapid forcefully fired spring mechanism can help combat this in many cases (Fig. 12.14a, b). Another useful trick in very dense tissue is using a 16 G instead of a 14 G. The smaller diameter will often pierce the tissue better and achieve nice specimens, especially of “hard” lesions.

A coaxial introducer may be used in conjunction with the biopsy gun. The introducer is placed similar to the needle placement described previously. Introducers are typically extremely sharp and do not usually require a skin incision. The trochar is then removed and the biopsy needle is placed through the introducer and into proper position to obtain a sample. This allows multiple samples to be obtained with only a single skin puncture. It decreases trauma to the surrounding tissue and can be very useful in dense, difficult to penetrate tissue.

In cases where automatic deployment is not safe, a device with a manual mode is advantageous. The Achieve® biopsy device (Cardinal Health, Dublin, OH) is available in several gauges, and the stylet can be deployed independently from the cutting cannula. An introducer must first be placed. The device, with the stylet prefired, is placed thru the cannula and the sample notch can be positioned as desired within the mass. The cutting cannula is then deployed directly over the stylet, with no additional needle tip forward advancement. This can be very useful in cases with masses very near implants or other sensitive structures.

After obtaining a sample the needle is removed. Manual pressure should be applied over the incision by the technologist while the needle is out to aid in hemostasis and decrease bleeding. Care should be taken to maintain sterile technique. Tweezers or the tip of a needle can be used to remove the specimen from the sample notch and place it into formalin. Care should be taken not to crush or damage the specimen. A small amount of normal saline from a sterile syringe can also be used to “wash” the specimen out of the notch. The needle should not be placed directly into the formalin, as this would introduce a caustic substance into the patient. Some centers prefer to swish the needle tip in a small test tube of normal saline to remove the specimen. This can subsequently be transferred to a formalin container. The macroscopic evaluation of the specimen can yield important information regarding quality. Intact, firm, white or dark red-brown cores that sink are favorable signs. Fragmented, yellow, floating oily cores are less likely to yield a conclusive diagnosis.

As per the ACR Guidelines, 3–6 core samples are generally recommended [15]. Several authors have advised not be “dogmatic” about the number of cores, with the exact number based on case-by-case assessment. Decisions regarding the optimal number of specimens should take into account the radiologist overall confidence in the specimens. Factors to consider include how well the lesion was seen before and during the procedure, needle location pre- and postfire, and visual evaluation of the specimen [16, 22].

A study by Szynglarewicz [29] found a median pain rate of 4 (on an 11-point visual analogue scale of pain; 0 = none 10 = extreme) in women undergoing US-guided core biopsy. Specifically they compared pain experienced by patients undergoing US-guided biopsy with either a 14-gauge automated core needle or an 11-gauge vacuum-assisted CNB. Despite the larger gauge, the study found that less pain was experienced in the VA biopsy group. The authors believe this is due to contiguous collection of tissue without removing the needle. They reference similar findings in other studies. They also point out that while some studies indicate more pain with an 11-G VA needle biopsy than with a 14-G ASL needle biopsy, these studies were comparing 11 stereotactic procedures with 14-G US-guided procedures. The findings may be related to inherent differences in stereotactic guidance versus US guidance (longer procedure time, prone positioning, compression, etc.).

Most studies indicate hematoma formation and bleeding are more common in VA biopsies than in ASL biopsies [1, 5, 27, 30]. The fairly straightforward argument holds that a larger biopsy cavity creates more bleeding. A few studies demonstrate that hematoma/bleeding is less common (or equal) in VA biopsies compared to ASL biopsies [29, 31]. These authors argue that although more tissue is removed, the single insertion with subsequent decreased tissue trauma and the ability to evacuate the biopsy cavity with vacuum actually decreases hematoma formation.

Although implant rupture is a risk, it is very low given the real-time imaging capability. In addition, manual devices such as the previously mentioned, Achieve®, and VA devices that do not require a “throw” can be helpful in challenging cases. Both stereotactic and US-guided biopsies are safe and accurate in augmented breasts [32].

Seeding of biopsy needle track with viable malignant cells was an initial concern with all diagnostic breast needle procedures. Tissue seeding has been reported in 37 % ultrasound-guided ASL biopsy and in 23 % of the cases following VA biopsy [16]. In a prospective study from the Netherlands [33], seeding was not felt to be clinically significant, as radiotherapy is performed and conclusions were that tumor cells do not survive displacement.