This is an updated and revised version of an article which appeared in Surigcl Technology International VII Expanding The Role of Technology: Stereotactic Breast Biopsy in the Mobile Environment
	Author Charles M. Elboim, M.D.

Abstract Mammography continues to be the best available screening modality to find early stage breast cancer. However, many abnormalities seen on mammography turn out to be benign. In response to the large number of negative biopsies being performed, minimally invasive breast biopsy techniques have been developed. During the last decade, digital stereotactic imaging and biopsy technology have matured to the point that they now offer major benefits over traditional open surgical wire guided localization breast biopsy in terms of accuracy, morbidity and cost. However, the purchase price of this technology has limited its widespread use. Placing prone stereotactic tables in a mobile coach allows physicians in small and medium sized hospitals and surgicenters to perform stereotactic biopsies by sharing the technology among multiple users. The development of standard approaches via patient care algorithms and the improved communications through meetings of User groups have allowed mobile stereotaxy to provide high quality service to outlying medical facilities. The sharing of expensive minimally invasive breast biopsy technology is now allowing women in small cities and towns in the U.S. to receive the same quality of care as their counterparts living near major medical centers. By placing digital stereotactic and ultrasound systems in mobile coaches, entrepreneurs have filled a niche in the health care system that affects the lives of hundreds of thousands of women yearly. Image-guided breast biopsy has been shown to be an almost painless, highly accurate, minimally invasive method of biopsying mammographic abnormalities without the cost and scarring of open biopsies.(1-12) Since 80% of mammographic abnormalities which are biopsied turn out not to be breast cancers, this technique spares many women an unnecessary operation. The method requires only a 3-4 mm (1/8th of an inch) incision and narrow gauge needles or probes to acquire tissue with an accuracy rate that approximates or betters that of open biopsy (6, 10-12)There are far fewer complications and no associated cosmetic deformities. In addition, multiple studies have shown stereotactic biopsy to be more cost-effective than open biopsy in both moderate and high suspicion lesions(7-9). Between $500 and $1000 can be saved per biopsy when stereotactic and ultrasound-guided biopsy are substituted for wire-guided open surgical biopsy. It has been estimated that up to 23% of the entire cost of the breast cancer screening program in the U.S. could be saved if stereotactic biopsy were substituted for open surgical biopsy(9). Consequently, patients, physicians and health insurers have recognized its value, with the number of stereotactic biopsies in the U.S. alone growing from a few hundred in 1990 to an estimated 300,000 in 1995(13). Unfortunately, most small and medium sized hospitals, ambulatory surgery centers, medical imaging centers and private surgeons cannot afford the expense of such technology. Faced with declining revenues and scarce resources, many medical institutions fear the burdens of a large capital outlay, the setting aside of expensive real estate, the cost of service contracts service contracts as well as the training and retention of skilled personnel for an infrequently-used device. Moreover, the device is useful for performing a single task, i.e., breast biopsy. As a consequence, at small institutions, surgeons either perform the open surgical excisional method or send their patients to large centers that can afford the technology. However, once patients receive their care elsewhere, there is always the fear that they will not return to their original physicians and medical centers in the future. Some patients live so far away from centers possessing the technology that they undergo the open operation rather than spend many hours in travel. Some are not even apprised of the fact that such an option is available elsewhere. Mobile Stereotaxy World's first mobile stereotactic breast biopsy facility, developed by United Technologies for MoBx. Enter the mobile concept, which had been used successfully in the fields of mammography, CT, MRI, and shock wave lithotripsy. In 1993, United Medical Technologies, Inc. (now MoBx) developed the nation's first mobile stereotactic system for MoBx, a group of small hospitals and medical imaging centers in Northern California. At that time, few people knew what a stereotactic biopsy was and there were no guidelines, rules or regulations as to its usage. The entire concept had to be explained to California State regulators, physicians, insurance companies, HMOs and patients. With the help of radiologists, surgeons, hospital administrators and health insurance officials, MoBx developed patient care algorithms, information packets for physicians and patients, and database tracking methods to satisfy the various needs of the different factions of the health care industry. The prone stereotaxy table was chosen instead of the add-on upright machine since it provides greater patient comfort and doesn't allow the patient to see a large bore needle coming toward her breast. Since any deviation from the intended target could lead to an inaccurate or missed diagnosis of cancer, any patient movement has to be minimized. The prone position also precludes the patient from seeing any bleeding that might develop. Vasovagal episodes are quite rare in this position, while they terminate wire localization in up to 1.2% of cases. The main concern was that the technology be used appropriately and well. No one wanted a breast cancer to be missed and, therefore, Quality Control became of paramount importance. The physicians performing the biopsies, the pathologists reading the slides and the medical staffs at each hospital were given guidelines and Continuing Medical Education lectures about stereotactic biopsies. Initially some physicians were reluctant to embrace the new technology and some insurers refused to pay for the procedure. In addition, it took almost a year after the facility started operating before certain major insurers certified the procedure. However, growth has been rapid since that time. Since clinical biopsies started being performed in June, 1994, UMT's client base has doubled, from five centers in a small geographic locus to ten centers in 1997. In 1999, over 20 medical centers are being served in California, Nevada with expansion plans for Arizona, Oregon and Washington states in the near future. UMT has continued its clinical approach by providing the physician and patient with exactly the same environment as found in a fixed site. The latest Fischer ImagingTM or Lorad DSM digital stereotactic mammographic imaging equipment, a fully trained mammographic technologist, and a software database program which tracks all the procedures and patients are provided on-site. The physicians performing the biopsy determines which tissue acquisition systems are used. An immediately available written operative note and list of CPT codes are given to the physician at the end of each procedure and hard copy is kept for archiving. Alternatively, images can be archived on optical disk. Patient Acceptance Initially, there was concern that women would have difficulty with the idea of going into a "truck" for a breast biopsy. However, the prior use of mobile facilities for mammography, MRI and lithotripsy made the concept easier to accept, as there have been few problems with patient acceptance with these mobile systems. In addition, every effort is made to provide an environment as warm and soothing as possible, including the use of local artwork. There is much more room inside than is immediately apparent. Privacy is maintained by having the patient walk into the mobile facility and disrobe inside in a separate dressing room. The entire facility duplicates the ambiance and function of any radiologic facility. As a testimony to the fact that women do feel comfortable having biopsies done in this environment, follow-up patient satisfaction questionnaires have been uniformly laudatory. For patients, the experience is totally unlike that of an open biopsy. No preoperative lab tests, EKG's, pre-admission visits to the hospital, phone calls or visits by an anesthesiologist are necessary. Instead of a 3-4 hour hospital stay, a trip to the OR, and recovery room visit, a process which can sometimes more than half a day, the entire process for a stereotactic biopsy takes one hour. The patient leaves with a 3-4-mm. scar, a few steristrips and a bandage. No sutures are inserted. In addition, post-operative pain relievers are unnecessary. Physician and Technologist: Working Partnership MoBx's mammography technologists are specially trained in stereotactic biopsies and soon acquire a wealth of experience. Most have performed many hundreds or thousands of biopsies and have worked with a large number of physicians. This exposure to many approaches has allowed them to learn many innovative methods which technologists in small institutions would never be able to acquire. They take the best ideas from each physician and teach the others. The establishment of a Users' Group has also facilitated the free flow of ideas. This interplay allows the physicians and technologists to avoid a syndrome common in small institutions of limited exposure to new ideas. One small local hospital with their own prone table asked MoBx's technologists for help as they were having trouble with the MammotomeTM system. MoBx's technologists soon realized that the techs and physicians at this small institution had been using the MammotomeTM incorrectly for some six months! At one of MoBx's mobile facilities, this could never happen. The technologists help the patients by calmly and thoroughly explaining the procedure before the physician arrives. They not only position the patient in as comfortable a position as possible, they obtain all the early scout images and stereotactic pairs for the physician. All necessary instrumentation is laid out, minimizing down time for both the patient and physician. Experienced technologists can reduce physician time to only 20 minutes in many instances. Physicians performing the biopsies must go through an accredited training program and become credentialled by their respective institutions. The institutions provide their own physicians to do the biopsy as well as pathologists to read the slides. Since the cores provide pieces of tissue even larger than prostate core biopsies, the histologic samples can be read by a staff pathologist, rather than requiring the services of a cytopathologist. MoBx asks each physician to fill out database forms for each biopsy, which helps in patient tracking. MoBx's technologists then enter the data. Physician performance is reported on a yearly basis so that medical facilities can prove to surveyors that quality of care meets standards. UMT provides the mobile coach to contracting medical facilities on a regular schedule, (usually every one to two weeks) so that patients do not have to wait long periods of time for their biopsies. Inside the coach is a state of the art prone Fischer Mammotest PlusTM or Lorad DSM digital stereotactic imaging table and the Biopsys MammotomeTM biopsy device. The 12 or 14 gauge Bard Pro-MagTM (formerly Bip) spring loaded core needle device is also available. The needle in this device has to be taken out each time a piece of tissue is removed. The Mammotome14-16 systemTM uses 14 or 11 gauge probes that are inserted into the breast once only. After appropriate placement, made easier through the use of a directional thumbwheel, vacuum is applied to capture the mammographic abnormality and a high-speed cutter takes out a sliver of tissue. The tissue is removed via suction applied at a different point on the probe, so the probe never leaves the patient's breast until all the tissue has been harvested. The probe can take out multiple contiguous pieces of tissue in a clockwise or counterclockwise fashion or may be directed at an especially suspicious area on the mammogram. Often 15 separate pieces are removed in a relatively short time, as the system is so easy to use. An "air-hole" is seen on the immediate post-operative digital mammogram showing the area where the lesion used to be. Images are either printed on regular x-ray film or kept on optical disk, depending on the desires of the contracting institution. Hook-ups to laser cameras are easily accomplished. When the biopsy is performed for microcalcifications, radiographs are made of the tissue obtained to make sure the microcalcifications have been successfully removed(17). Wire placement for wire-guided (or needle) localization biopsy is easily performed using digital imaging on the prone table to an accuracy not possible through standard techniques (+/- 1 mm.). It takes only 15 minutes to place the wire this way. Future Plans Future plans include the use of ultrasound as another imaging modality for use with the Biopsys MammotomeTM or BardTM gun. The use of the prone table and mammography paddles has many advantages. First, no radiation is involved. Second, the patient is lying prone where she cannot see the technical aspects of the procedure. Third, the paddles allow compression and immobilization of the breast. Fourth, the table allows use of the MammotomeTM system, which is becoming the preferred method of tissue acquisition in most centers. When a regular ultrasound table is used, it is difficult to use the MammotomeTM, although Biopsys/Ethicon EndoSurgeryTM does sell a special table with an articulating arm for $10,000 US. By placing ultrasound capability on the stereotactic table, all the advantages of the prone table are maintained. The physician can then choose which imaging modality should be used, depending on which image is most easily seen. Now that the FDA has cleared the new hand-held Mammotome, the table can also serve as a platform for the patient who has to lie supine or rolled to the side. Again, the expense of buying the hand-held Mammotome is obviated when MoBx's facilities are used. MoBx is using the ImagynTM Site-SelectTM device that is used by surgeons to perform a larger tissue extraction using stereotactic imaging. This technology is attractive to surgeons who are dissatisfied with the amount of tissue that is removed with image guided core needle biopsies. In most instances, tissue is sufficient for accurate diagnosis with core needle systems. However, until the MammotomeTM system was introduced, approximately 50% of the cases diagnosed as atypical ductal hyperplasia (ADH) on stereotactic core-needle biopsy turned out to be ductal carcinoma-in-situ (DCIS) or an occasional infiltrating ductal cancer. Fortunately, only 4-9% of all biopsies show ADH. Thus, anytime ADH is found in a stereotactic core needle biopsy, open wire-guided surgical excisional biopsy is recommended. The same holds true for DCIS. The 11 gauge MammotomeTM system reduces, but does not entirely remove, that problem. An earlier large core system, the ABBITM device, takes out 5, 10, 15, or 20 mm. cylinders of tissue, starting from just below the skin level, capturing fat, normal breast tissue, the mammographic abnormality and approximately 1.0 - 1.5 cm of tissue beyond the lesion 18, 19. However, the Imagyn Site-SelectTM system appears to be easier to use in a mechanical sense and is designed to take out 10 or 15 mm. cylinders of tissue after it goes through normal fat and breast tissue, without capturing the normal tissue. Thus, less normal tissue is removed, minimizing cosmetic deformity. Both techniques require suturing of the skin, although skin-bonding adhesives may make suturing unnecessary in some instances. Control of bleeding through electrocautery is occasionally necessary. At present, research is underway to treat breast cancer through cryosurgery or laser energy delivered via the stereotactic approach. Animal studies have been performed that show that these forms of tissue destruction can be delivered in a controlled fashion. Spread of Mobile Stereotaxy Other mobile systems have been developed in the U.S., including sites in Texas, Florida, Iowa, Southern California and New England To date, however, only MoBx has a nationwide presence. It is actively working with groups of small hospitals, ambulatory surgery centers, health care systems, surgeons and radiologists who want to provide stereotactic breast biopsy to their patients in a cost-effective method. For individual hospitals and health systems, MoBx's services mean absence of worries about service contracts, maintenance costs, upgrades of hardware and software, training technologists, maintaining technologist schedules, the ordering and storing of supplies, etc. Mobile stereotaxy also makes sense for socialized medical care systems anywhere in the world, where resources are often limited. The sharing of expensive technology controlled by these systems can translate into efficient and effective use of this highly desirable diagnostic test. MoBx expects that there will be an increased demand for image-guided breast biopsies as insurers expand their analyses of how health care dollars are spent. With managed care penetrating the health care market in the U.S., and physicians and HMOs becoming financially responsible for health care expenditures, mobile stereotaxy offers a way to save substantial amounts of money. It also provides the service to all women, almost no matter where they live. And as women come to understand the marked advantage of stereotaxy for them personally, they end up choosing stereotaxy over open biopsy greater than 80% of the time. With mobile stereotaxy, they are grateful that they don't have to travel long distances to have their breast biopsies performed. References 1. Parker S, Lovin J, Jobe W, et al. Nonpalpable Breast Lesions: Stereotactic Automated Large-Core Biopsies. Radiology 1991; 180:403-407. 2. Elvecrog E, Lechner M, Nelson M. Nonpalpable breast lesions: Correlation of stereotaxic large-core needle biopsy and surgical biopsy results. Radiology 1993; 188:453-455. 3. Janes R, Bouton M. 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