Percutaneous Large Core Breast Biopsy

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256 Percutaneous Large Core Breast Biopsy Steve H. Parker, M.D. Background. Surgical excision biopsy is considered by many to be the gold standard for the diagnosis of breast lesions.

1 256 Percutaneous Large Core Breast Biopsy Steve H. Parker, M.D. Background. Surgical excision biopsy is considered by many to be the gold standard for the diagnosis of breast lesions. Fine needle aspiration biopsy is used by some radiologists and other physicians in an attempt to diagnose breast lesions nonsurgically. To overcome the drawbacks associated with both of these methods, the author and his coworkers have developed the image-guided automated large-core breast biopsy method. Methods. All biopsies are performed using either a dedicated, prone stereotactic device or high-resolution near-field ultrasound equipment for needle guidance. A long-throw (2.3 cm) automated core biopsy device fitted with a 14-gauge needle is used to acquire five or more core samples from each lesion for histologic evaluation. Results. The ability of percutaneous, image-guided, large-core breast biopsy to provide the correct histologic diagnosis of a breast lesion is equivalent to open surgical biopsy. The cost of large-core breast biopsy is one half to one quarter that of surgical biopsy. No adverse cosmesis or mammographic pseudolesion results. Conclusion. In an era of increasing cost restraints in health care, it is important to identify means by which the level of patient care can be maintained or improved at lesser cost. Percutaneous large-core breast biopsy provides that opportunity in the diagnosis of breast disease and should prove to be a cost-effective, reliable, and expedient alternative to surgical biopsy. Cancer 1994; 74: Key words: breast, biopsy, breast neoplasms, biopsies, technology, cost effectiveness. As breast cancer screening becomes more commonplace and the consequent number of diagnostic breast biopsies increases, the need for an effective, streamlined diagnostic workup of breast problems becomes more critical. The patient and the medical system are served best by a complete workup done in the shortest time using the least resources. By incorporating percutaneous, au- Presented at the National Conference on Breast Cancer, Boston, Massachusetts, August 26-28, From the Radiology Imaging Associates, Englewood, Colorado. Address for reprints: Steve H. Parker, M.D., Radiology Imaging Associates, 8200 East Belleview Avenue, Suite 124, Englewood, CO Accepted for publication January 31, tomated, large-core breast biopsy into the radiologist s armamentarium, this goal can be accomplished more easily. The accuracy of core breast biopsy is at least equal to that of traditional localization and open, surgical breast biopsy. - In addition, percutaneous core breast biopsy has significant advantages over surgical biopsy: no surgical scar will result from the biopsy and no mammographic pseudolesion is left within the breast to confuse future interpretation. The biopsy can be set up and performed much more quickly than surgical biopsy, even the same day that the breast abnormality is detected. If a patient undergoes a percutaneous core breast biopsy instead of a surgical biopsy and does not have cancer (which accounts for 7045% of all patients on whom breast biopsies are performed), she will be spared one surgery. If the patient does have breast cancer and the percutaneous core biopsy technique is used instead of surgery, she frequently will be spared the additional surgery of the initial diagnostic biopsy and can go directly to definitive therapeutic surgery. Furthermore, when a breast cancer is identified by percutaneous core biopsy, the surgeon performing the definitive therapeutic surgery has a much easier surgical field of operation. The surgeon does not have to operate on the distorted cavity created by a previous open, surgical biopsy. Finally, when percutaneous core breast biopsy ultimately replaces open, surgical breast biopsy, the potential cost savings for the United States will be as high as one billion dollars per year. The accuracy of the procedure depends on highly developed mammography and interventional skills and is, consequently, an advanced radiology procedure. Before instituting an image-guided percutaneous largecore breast biopsy service, it is essential that the proper equipment and radiologist s abilities are in place to ensure the appropriate workup and successful biopsy of suspicious breast lesions. High quality mammography is essential, as is state-of-the-art breast ultrasound. Ideally, the radiologist performing the biopsies should have expertise in mammography and ultrasound, and experience in interventional radiology. Radiologists and other specialists who do not possess these fundamental skills have no place directing this procedure.

In addition to standard two-view mammography, spot-compression and magnification-view capability are crucial for the appropriate mammographic problem solving that precedes biopsy.

2 Percutaneous Large Core Breast BiopsylParker 257 Figure 1. Dedicated prone stereotactic unit. These units eliminate unwanted patient movement and vasovagal reactions common to the adapted standard stereotactic units. In addition to standard two-view mammography, spot-compression and magnification-view capability are crucial for the appropriate mammographic problem solving that precedes biopsy. For mammographic biopsy guidance, the stereotactic images should be able to identify any lesion detected on a conventional mammogram. The dedicated recumbent stereotactic equipment generally is regarded as being better suited to large-core breast biopsy than are adapted standard mammography or "add-on" units (Fig. 1). The recumbent stereotactic table can be raised, providing much more working room in and around the biopsy apparatus and X-ray tube than do "add-on" systems. Patient movement is rarely a problem with the recumbent units, as opposed to the "add-on" units in which patient movement can be responsible for a lesion miss. Furthermore, with the recumbent approach, vasovagal reactions are virtually nonexistent, and the patient is not subjected to direct observation of the biopsy itself as she is with the "addon" units. Lying on the table for long periods of time can be somewhat uncomfortable, however, and most patients find this worse than the actual biopsy. Digital, near real-time stereotactic imaging combined with a motorized, automatic guiding device for the biopsy apparatus can reduce procedure time considerably and has partially remedied this problem. Unfortunately, the cost differential between "addon" and dedicated stereotactic equipment is considerable. Compared to other high-tech imaging equipment, however, the cost is quite low. In addition, these resources committed to the early detection of breast cancer are arguably better spent than the considerable rethat have been devoted to many Other endeavors Of dubious (e.g./ gallstone lithotripsy). With respect to adjunctive diagnostic measures, breast evaluation has been improved markedly with the relatively recent significant improvements made in near-field ultrasound imaging. Older, conventional ultrasound equipment, however, cannot support the kind of decision-making required for breast biopsy. It is critical to have state-of-the-art ultrasound equipment with high frequency ( mhz), electronically focused, linear array transducers configured specifically for breast imaging. The near-field resolution must be superb and have the ability to focus electronically with multiple focal zones in the first 5-20 mm. Older or less expensive equipment is not suitable for good breast ultrasound. In addition to the appropriate imaging equipment for workup and biopsy guidance, large (14-gauge) needles are required to obtain surgical quality tissue. Compared with the cytologic material obtained with fine needle aspiration biopsy (FNAB) (Fig. 2), core biopsy provides histologic tissue that allows definitive diagnoses. For benign lesions, this is especially important. Rather than the cytologic diagnosis of "no malignancy present," a definitive diagnosis such as intracanalicular Figure 2. Comparison of cytology from fine needle aspiration biopsy with histology from core biopsy. (Top) This cytology smear shows malignant cells, but it is impossible to determine whether the cancer is invasive or in situ. (Bottom) Core histology demonstrates a definitive diagnosis of infiltrating ductal carcinoma.

258 CANCER Supplement July I, 2994, Volume 74, No. 1 Figure 3. Example of benign core histology. Core biopsy specimen demonstrates an unequivocal diagnosis of a pericanalicular fibroadenoma.

In addition, if there is an extensive intraductal component coexisting with the infiltrating carcinoma, this likewise can be targeted and diagnosed on large-core biopsy.

3 258 CANCER Supplement July I, 2994, Volume 74, No. 1 Figure 3. Example of benign core histology. Core biopsy specimen demonstrates an unequivocal diagnosis of a pericanalicular fibroadenoma. No surgery is required. drawbacks. In addition, if there is an extensive intraductal component coexisting with the infiltrating carcinoma, this likewise can be targeted and diagnosed on large-core biopsy. Armed with this refined information, the therapy team is generally more aggressive in their treatment plan. Not only does the large-core technique allow for more definitive benign and malignant diagnoses, it eliminates several drawbacks of FNAB: the significant insufficient tissue rate, the need for a pathologist or cytotechnologist to attend the biopsy, and the need for a cytopathologist to interpret the It is equally important that the core tissue be obtained with an automated, large-core biopsy device to fibroadenoma can be rendered (Fig. 3). Therefore, it is possible to differentiate between a false negative histologic diagnosis, due to sampling error, and a true negative one, such as fibroadenoma. This distinction frequently is not possible with FNAB. The possibility of a false negative result will always haunt FNAB and frequently results in the need for a surgical biopsy to confirm the benign nature of a mass. The patient and surgeon understandably might wonder in these instances whether or not the skinny needle either missed the lesion or was in the lesion but failed to obtain adequate cells for diagnosis of a possible malignancy. This kind of uncertainty makes it difficult to substitute breast FNAB for surgical excision biopsy and therefore makes FNAB another additional layer of cost and testing on top of surgical excision biopsy. Histologic evaluation of core tissue also can exactly classify any malignancy present. This streamlines appropriate treatment planning and implementation. With cytology, not knowing whether a cancer is invasive complicates and potentially lengthens the definitive surgical procedure. By obtaining more definitive malignant diagnoses with the core tissue (Fig. 4), the patient can be counseled confidently regarding the therapeutic options, and therefore, the appropriate therapeutic procedure can be chosen rationally. This is especially true for differentiating in situ from invasive carcinoma. If the cancer is found to be invasive on the permanent section core histology, then the patient can be counseled appropriately regarding lumpectomy versus mastectomy. If the patient opts for lumpectomy, then the lymph node dissection can be done at the same time, reducing the number of surgeries from two to one. If the patient opts for mastectomy, this can be confidently performed without the need of frozen section confirmation and its attendant Figure 4. Bilateral breast calcifications. Stereotactic core biopsies were performed on both areas. The histologic diagnosis of infiltrating ductal carcinoma was obtained from the lesion in the lower aspect of the right breast, and a diagnosis of degenerated fibroadenoma was made from the cores obtained from the upper left breast lesion. Therefore, appropriate treatment planning can be initiated for the right breast lesion, and the left breast lesion can be dismissed.

4 Percutaneous Large Core Breast Biopsy/Parker 259 realize the fruits of the efforts expended on pinpoint image guidance. The rapid excursion of the needle with this equipment allows for accurate sampling of mobile breast lesions such as fibroadenomas before they have the opportunity to slip out of the path of the needle. In addition, patient discomfort is minimized, and there is little or no crush artifact, as there is with manual core biopsy techniques. These samples are of much higher quality than those obtained with conventional manual 14-gauge needles7 As important as the proper equipment may be, the proper personnel must be in place to operate the equipment. The technologists operating the equipment must be highly trained and skilled. More importantly, the radiologists should be well trained and experienced in all aspects of breast imaging. The radiologist also should have extensive experience in performing image-guided needle biopsies and other interventional procedures. The optimum, of course, is a radiologist skilled in mammography, ultrasound, and interventional radiology. A radiologist who can master and blend these three areas of expertise can insure appropriate breast workup and ultimately perform large-core breast biopsy to its best advantage. Physicians who are not radiologists are unlikely to have extensive training and experience in these three areas, and it therefore would seem unwise for these individuals to direct the procedure. The indications for large-core breast biopsy, with ultrasound or stereotactic guidance, are essentially the same as those for surgical biopsy. Compared with surgical biopsy, however, image-guided percutaneous biopsy is especially useful in patients with lesions seen well in only one projection or with multiple lesions in one or both breasts, and in postsurgical biopsy or lumpectomy patients with questionable lesions. In the sequence leading up to the decision to perform a biopsy, any and all clinical or mammographic areas of suspicion must be evaluated thoroughly. High quality ultrasound is especially important in evaluating mammographically dense breasts, where there is an area of clinical concern, and in better characterizing mammographically detected lesions that are still unclear after appropriate mammographic workup. Ultrasound guidance is uniquely suitable for lesions seen only on ultrasound and for patients who are nursing. In addition, if the lesion is seen well on both ultrasound and mammography, ultrasound guidance is preferred because it is quicker, less uncomfortable for the patient, and produces no ionizing radiation. If ultrasound verifies that a suspicious lesion is a nonpalpable, simple cyst, it safely can be left alone. If the cyst is palpable and/or symptomatic, it then can be aspirated easily using ultrasound guidance (Fig. 5). In cysts with questionable mammographic findings, a postaspiration mammogram can be performed to demonstrate that the mammographic lesion has resolved. There is generally no need to send the fluid from a simple cyst for analysis. Complex cysts are aspirated for two reasons. First, there is a small but real chance that a complex cyst is associated with malignancy and the fluid obtained may contain malignant cells. Second, solid lesions occasionally are mistaken for complex cysts. The inability to aspirate a presumed complex cyst suggests that the lesion is solid, and the radiologist then can proceed with ultrasound-guided core biopsy. In questionable ultrasound cases, verification that the lesion represents the suspicious mammographic lesion can be made by placing a 25-gauge hypodermic needle or retractable hook-wire needle into the lesion under ultrasound guidance. A postlocalization mammogram then is performed to prove unequivocally that the lesion seen on ultrasound is the same as that seen on mammography. A biopsy using ultrasound guidance then can be performed on the lesion. When it comes to the actual biopsy, the interventional skills of the radiologist are especially emphasized. The first step in stereotactic biopsy is to take a straight craniocaudal or mediolateral scout film. Two 15-degree off-axis stereotactic views are exposed side-by-side on a single film (Fig. 6, top left). The Biopty gun (Bard Radiology, Covington, Georgia) then is locked into place in its dedicated housing. The stereo views are placed on the adjacent digitizer, and the coordinates are calculated by activating a hand-held computer "mouse" at the center of the lesion and at reference cross hairs in each view. This process is performed on the computer monitor when using a stereotactic unit configured with digital imaging. Older units print out the lesion coordinates, which must be dialed manually into the biopsy holder. Units with an "autoguide" place the coordinates automatically in the memory of the remote control panel attached to the main unit. The biopsy gun and needle automatically align on the proper trajectory with a push of a button. After a small amount of local anesthetic is instilled, the gun and needle are advanced to the designated depth, and stereo views are repeated to confirm the position of the needle (Fig. 6, top right). After the gun is fired, a final set of stereo views is obtained to document that the needle has traversed the lesion (Fig. 6, bottom). At least five passes are made to obtain representative samples throughout the lesion. For calcification cases, a minimum of ten cores are obtained to thoroughly canvass the region. A magnified specimen radiograph then is obtained to verify that some of the target calcifications are included in the cores. Stereotactic units that are equipped with digtal imaging provide a faster verifica-

(Bottom) Ultrasound image showing resolution of a cyst iubsequent to vacuum activation. tion of the adequacy of biopsy.

5 260 CANCER Supplement July I, 1994, Volume 74, No.1 2igure 5. Cyst aspiration. (Top left) Symptomatic cyst as seen on iltrasound. (Top right) Ultrasound image showing a 21-gauge iacutainer needle within cyst before the activation of the vacuum of a ed top tube. (Bottom) Ultrasound image showing resolution of a cyst iubsequent to vacuum activation. tion of the adequacy of biopsy. A stereo pair of images can be performed after the requisite cores have been obtained to determine if some of the calcifications have been removed. In addition, small pockets of air noted throughout the region of biopsy are an additional verification of the adequacy of the complete canvassing of the region. A specimen radiograph still is performed, but the patient can be released from the table before this formality is completed. The same protocol for biopsy described above is used for ultrasound-guided biopsy, except that ultrasound is used for the image guidance portion. The freehand technique for ultrasound-guided biopsy is preferred (i.e., the radiologist holds the transducer in one hand and the biopsy needle in the other) (Fig. 7). In this way, the transducer and needle can be coordinated more easily without the constraints of a needle guide attached to the transducer. With the free-hand technique, the needle is advanced to and fired through the lesion under real-time ultrasound observation. Continuous observation also ensures avoidance of the chest wall. Pre- and postfire images are obtained to document the needle and sample notch passing through the lesion (Fig. 8). Of more than 1500 patients who underwent biopsies with the ultrasound and stereotactic percutaneous large-core technique, none experienced significant hematoma or other complication. In conclusion, because the breast is one of the few areas of the body still subjected to open surgical biopsy and surgical biopsy has some shortcomings, it is important to try and identify an alternative to surgical excision biopsy. In recent years, improved needle and imaging techniques have allowed percutaneous needle biopsies to replace open surgical biopsy in most other areas of the body. Excisional biopsy, however, remains the current standard for the breast. Most radiologists who have attempted to extend percutaneous biopsy to breast lesions have used FNAB. Although somewhat successful

Percutaneous Large Core Breast Biopsy/Parker 261 Figure 6. Stereotactic biopsy. (Top left) Stereotactic scout views of lesion with intended biopsy sites marked on the film.

(Bottom right) Second postfire view after retargeting, demonstrating the needle traversing the center of the lesion.

On the other hand, the combination of large-core automated biopsies and pinpoint imaging provided by stereotactic mammography and ultrasound can provide reliable, definitive histologic diagnosis of

6 Percutaneous Large Core Breast Biopsy/Parker 261 Figure 6. Stereotactic biopsy. (Top left) Stereotactic scout views of lesion with intended biopsy sites marked on the film. (Top right) Pre- and (bottom left) postfire views showing the position of the needle to be slightly low (anterior). (Bottom right) Second postfire view after retargeting, demonstrating the needle traversing the center of the lesion. The remainder of the cores then could be taken without the need for further stereotactic images. in other areas of the body, FNAB has its greatest failings in the breast. On the other hand, the combination of large-core automated biopsies and pinpoint imaging provided by stereotactic mammography and ultrasound can provide reliable, definitive histologic diagnosis of both benign and malignant breast lesions, thus providing a dependable alternative to surgery. In an era of increasing cost constraints in medicine, it is essential to identify means by which the level of patient care can be maintained or improved at a lesser cost. Percutaneous large-core breast biopsy provides that opportunity in the diagnosis of breast disease. With an accuracy similar to or better than that of surgical biopsy but with less Figure 7. Ultrasound biopsy, The preferred technique is the "freehand" technique, wherein the radiologist holds the transducer in one hand while guiding the needle with the other. Figure 8. Ultrasound biopsy. (Top) Pre- and (bottom) postfire images of the 14-gauge needle before and after the activation of the biopsy gun. The histologic diagnosis was infiltrating duct carcinoma.

7 262 CANCER Supplement July I, 2994, Volume 74, No. 1 psychologic and physical dmomfort than that experienced with and a cost one half to one fourth that of surgical biopsy, large-core breast biopsy should prove a cost effective, reliable, and expedient alternative to surgical biopsy. References 1. Norton LW, Zeligman BE, Pearlman NW. Accuracy and cost of needle localization breast biopsy. Arch Surg 1988; 123: Parker SH, Lovin JD, Jobe WE, Burke BJ, Hopper KD, Yakes WF. Nonpalpable breast lesions: stereotactic automated large-core biopsies. Radiology 1991; 180: Parker SH, Jobe WE, Dennis MA, Stavros AT, Johnson KK, Yakes WF, et al. US-guided automated large-core breast biopsy. Radiology 1993; 187: Elvecrog E, Lechner MC, Nelson MT. Non-palpable breast lesions: correlation of stereotaxic large-core needle biopsy and surgical biopsy results. Radiology 1993; 188: Meyer JE. Value of large-core biopsy of occult breast lesions. AIR Am IRoengenol 1992; 158: Dronkers DJ. Stereotaxic core biopsy of breast lesions. Radiology 1992; 183: Parker SH, Hopper KD, Yakes WF, Gibson MD, Ownbey JL, Carter TE. Image-directed percutaneous biopsies with a biopsy gun. Radiology 1989; 171: Parker SH, Lovin JD, lobe WE, et al. Stereotactic breast biopsy with a biopsy gun. Radiology 1990; 176:

CURRENT METHODS IN IMAGE GUIDED BREAST BIOPSY

CURRENT METHODS IN IMAGE GUIDED BREAST BIOPSY Stuart Silver April 24, 2004 OBJECTIVES Review development of current techniques Discuss stereotactic breast biopsy Discuss US guided breast biopsy 1 OBJECTIVES