Patent Publication Number: US-7715523-B2

Title: System and apparatus for rapid stereotactic breast biopsy analysis

Description:
This application is a nonprovisional application of, and claims priority to, U.S. Provisional Application No. 60/827,327, filed Sep. 28, 2006, which is incorporated by reference as if fully recited herein. 

   TECHNICAL FIELD 
   Exemplary embodiments of the present invention relate to methods (e.g., medical non-surgical) of diagnosing breast cancer and, more particularly, to a novel apparatus, system, and method which beneficially improves current stereotactic breast biopsy devices and methods. 
   BACKGROUND OF THE ART 
   Stereotactic breast biopsy has become the method of choice for the non-surgical diagnosis of many forms of breast cancer. Many breast cancers are discovered by the presence of microcalcifications visible on a screening mammogram. Yet, these microcalcifications do not have a corresponding palpable abnormality. Therefore, an image-guided needle biopsy technique must be utilized to determine if early, pre-invasive breast cancer is present. Currently, stereotactically guided needle biopsy procedures represent the state-of-the-art for the common situation outlined above. 
   However, though very safe and minimally invasive, stereotactic breast biopsy can be laborious, time-consuming and uncomfortable for the patient. The procedure requires the patient to be prone. In order to immobilize the breast, physical compression must be applied to the breast during the procedure, and the patient must remain motionless. Procedure times are typically between 30-45 minutes, despite recent advances in vacuum-assisted biopsy needle technology. A significant component of procedure time continues to be consumed by the film development cycles required for specimen radiograph production. 
   A specimen radiograph is an ex-vivo x-ray picture of the biopsy samples or specimen “threads” retrieved from the breast. Under conventional circumstances, this radiograph must be performed outside the procedure room on a standard mammography x-ray unit. This picture is required to assure that sufficient quantities of microcalcifications are removed from the groups of calcium targeted within the breast. This process proves that the biopsy procedure will be adequate for subsequent analysis by surgical pathology. The process of performing specimen radiography is standard-of-care for stereotactic breast biopsy. Each specimen radiograph cycle can last 5-10 minutes, thereby adding 20-30% additional procedure time. If the original specimen radiograph demonstrates a paucity of microcalcifications, additional biopsy samples must be harvested, and the specimen radiograph cycle must be repeated. 
   SUMMARY OF THE INVENTION 
   One exemplary embodiment of the present invention is a modification and improvement to the commercially available stereotactic biopsy systems (e.g., LORAD Medical Systems Corp., Danbury, Conn. or Fischer Medical Technologies, Inc., Denver, Colo.). This modification may allow the stereotactic, swing-arm x-ray source (currently used solely to guide the biopsy procedure) to be used in the rapid production of specimen radiography. In one exemplary embodiment, a mechanical track may allow the x-ray source to shift laterally from the working biopsy corridor (occupied by the patient&#39;s breast during a procedure) allowing the x-ray source beam to be aligned with an add-on digital image receptor card which may be added to the lateral aspect of the existing image receptor. The harvested biopsy specimen threads may be positioned in, for example, specimen slots on a disposable specimen cassette or holder. The disposable specimen holder may then be attached to the add-on digital image receptor card between the x-ray source and digital image receptor card to allow for instant production of specimen radiographs within the procedure room. Other exemplary embodiments are possible as set forth herein. 
   Some examples of the benefits may include, but are not limited to, the following: 
   a) Production of instant digital (rather than analog) specimen radiographs in the procedure room can be achieved. This feature can reduce procedure time up to 30%, thereby improving patient tolerance of the procedure. 
   b) Bleeding complications and needle discomfort can be diminished, as the typical number of samples harvested by the operator may decrease with exemplary embodiments of the present invention. There may no longer be a disincentive to “view” the biopsy sample early in the procedure, after a few samples have been retrieved.
 
c) The digital specimen radiograph can be “post-processed” (filtered and windowed) to assure adequate visualization of very small, subtle microcalcifications, (many of which may be less than 0.1 mm in diameter). This feature may improve the accuracy of stereotactic biopsy. With analog specimen radiography, these types of microcalcifications can be very difficult to reliably identify, resulting in the need for additional biopsy retrieval.
 
d) Decreased procedure time may allow for more procedures to be performed within a given time and level of staffing commitment. This may improve the economic viability of this procedure for biopsy centers.
 
   These and other advantages may be provided by exemplary embodiments of the present invention, as described in more detail below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other aspects of exemplary embodiments of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments. 
       FIG. 1  illustrates an example of a breast biopsy specimen radiograph showing microcalcifications. 
       FIG. 2  illustrates a front perspective view of a typical stereotactic biopsy system (commercially available from LORAD). 
       FIG. 3  illustrates a perspective view of a typical stereotactic biopsy system (commercially available from LORAD) showing details of the swing-arm x-ray source subassembly. 
       FIG. 4  illustrates a perspective view of a typical stereotactic biopsy system (commercially available from LORAD) showing details of the swing-arm x-ray source subassembly. 
       FIG. 5  illustrates a perspective schematic view of a typical stereotactic biopsy system showing exemplary components. 
       FIG. 6  illustrates a top plan schematic view of a typical stereotactic biopsy system showing exemplary components without a patient table. 
       FIG. 7  illustrates a perspective schematic view of an exemplary embodiment of a stereotactic biopsy system of the present invention with the x-ray source in a stowed configuration. 
       FIG. 8  illustrates a top plan schematic view of an exemplary embodiment of a stereotactic biopsy system of the present invention with the x-ray source in a stowed configuration. 
       FIG. 9  illustrates a perspective schematic view of an exemplary embodiment of a stereotactic biopsy system of the present invention with the x-ray source in a deployed configuration. 
       FIG. 10  illustrates a top plan schematic view of an exemplary embodiment of a stereotactic biopsy system of the present invention with the x-ray source in a deployed configuration. 
       FIG. 11   a  illustrates a perspective schematic view showing one example of a specimen cassette with the specimen cover in an open position. 
       FIG. 11   b  illustrates a perspective schematic view showing one example of a specimen cassette with the specimen cover in a partially closed position. 
       FIG. 11   c  illustrates a perspective schematic view showing one example of a specimen cassette with the specimen cover in a closed position. 
       FIG. 12  illustrates a perspective exploded schematic view showing one example of a specimen cassette positioned for insertion onto a digital imaging receptor card. 
       FIG. 13  illustrates a perspective schematic view showing one example of a specimen cassette positioned onto a digital imaging receptor card. 
       FIG. 14  illustrates a perspective schematic view of another exemplary embodiment of a stereotactic biopsy system of the present invention. 
       FIG. 15  illustrates a top plan schematic view of an exemplary embodiment of a stereotactic biopsy system of the present invention with the x-ray source in a rotated configuration. 
       FIG. 16  illustrates a top plan schematic view of the present invention with an x-ray source and digital imaging receptor in respective stowed configurations. 
       FIG. 17  illustrates a top plan schematic view of an exemplary embodiment of an x-ray source and digital imaging receptor in respective deployed configurations. 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) 
     FIG. 1  illustrates a typical specimen radiograph showing a needle aspirated biopsy specimen  45  and microcalcifications  55 . Biopsy specimens similar to  45  may be harvested from a patient&#39;s breast  25  typically via a plurality of samples collected from a target area  35 . The specimen radiograph is an ex-vivo x-ray picture of the biopsy samples retrieved from the breast, which under conventional circumstances, must be processed outside the procedure room, on a standard mammography x-ray unit or on a separately purchased commercially available unit, such as one produced by Faxitron X-ray Corporation, Wheeling, Ill. In the current state of the art, this picture is required to assure that sufficient quantities of microcalcifications are removed from the groups of calcium targeted within the breast. 
     FIGS. 2 ,  3 , and  4  illustrate a typical example of a commercially available stereotactic biopsy system  10  produced by LORAD Medical Systems Corp., Danbury, Conn. During a typical biopsy collection procedure, a patient is positioned in a prone position on table  20 . The patient&#39;s breast under examination is allowed to protrude through a port  30  in table  20  and is captured and stabilized between a digital imaging receptor  40  and needle stage  50 . The x-ray source  60  illuminates the breast with x-ray radiation forming an image on the digital imaging receptor  40 , located on the distal side of the breast relative to x-ray source  60 , for subsequent image processing. The collected x-ray image is reviewed and post-processed on a connected computer console and system in the procedure room. Foundation  80  and base  90  are rotatably connected which allows the physician to orient the x-ray source  60  and digital imaging receptor  40  to produce stereotactic image pairs that allow the physician to accurately position the tip of the biopsy needle (in x, y, and z coordinates) within the patient&#39;s breast. 
   Referring now to  FIGS. 5 and 6 , the x-ray source  60 , which is fixedly attached to foundation  80 , projects a radiation beam along a working biopsy corridor along beam axis  110  (occupied by the patient&#39;s breast during a procedure). During a typical biopsy harvesting procedure, a specimen radiograph is produced via an ex-vivo x-ray image of the biopsy samples retrieved from the breast. Under conventional circumstances, this radiograph must be performed outside the procedure room on a standard mammography x-ray unit or on a separately purchased Faxitron unit. This radiograph is required to assure that sufficient quantities of microcalcifications are removed from the groups of calcium targeted within the breast. This process proves that the biopsy procedure will be adequate for subsequent analysis by surgical pathology. Each specimen radiograph cycle can last 5-10 minutes, thereby adding 20-30% additional procedure time. If the original specimen radiograph demonstrates a paucity of microcalcifications, additional biopsy samples must be harvested and the specimen radiograph cycle must be repeated. 
   To provide quicker results, an exemplary embodiment of this invention may beneficially reduce the time needed to conduct the ex-vivo x-ray image processing steps described heretofore by allowing the physician to process and review x-ray images within a procedure room by means of modifications and improvements to, for example, commercially available stereotactic biopsy systems (e.g., LORAD, Fischer Medical Technologies, etc.). An example of this modification comprises a means by which the stereotactic, swing-arm x-ray source  60  (currently used solely to guide the biopsy procedure) may be, for example, displaced or rotated for use in concert with an image receptor to allow the rapid production of specimen radiography. 
     FIGS. 7 through 11  illustrate an example of one exemplary embodiment of the present invention wherein a mechanical track system  65 , which may be slidably attached to foundation  80  and support x-ray source  60 , allows the x-ray source  60  to be laterally displaced from the working biopsy corridor along beam axis  110  (otherwise occupied by the patient&#39;s breast during a procedure). An add-on ancillary digital image receptor  70  is introduced and preferably positioned adjacent to digital imaging receptor  40 , whereby the now displaced x-ray source beam  120  (shown in  FIG. 10 ) may be aligned with a digital image receptor  70  to allow x-ray beam axis  120  to impinge normally upon the ancillary digital image receptor face  150 , such as shown in the example of  FIGS. 12 and 13 . 
   A means for retaining collected biopsy samples within the apparatus for analysis may be provided by a wide variety of mechanical support schemes. As shown as one example in  FIGS. 11   a ,  11   b , and  11   c , harvested biopsy specimens  45  may be positioned in a specimen “cassette”  130  that may be fixedly or removably attached to an ancillary digital image receptor  70 , which may be, in-turn, fixedly or removably associated with digital imaging receptor  40 . In one exemplary embodiment, it may be preferable that the specimen cassette  130  be fabricated of x-ray transparent materials that are low in cost so as to promote disposability, such as paper-based materials or plastics, which may include, for example, polyethylene, polypropylene, polycarbonates, and polystyrenes, among others.  FIG. 11   a  illustrates one example of a cassette  130  design which comprises a cassette base  180  that is hingedly attached to a cassette lid  170  via hinges  190 .  FIGS. 11   b  and  11   c  illustrate one example of a cassette lid  170  closure scheme. Other cassette base and cassette lid closure schemes are possible. For example, one exemplary embodiment may include the use of interlocking tongues and grooves on the cassette base  180  and cassette lid  170 , which may allow for a slideable connection between cassette lid  170  and cassette base  180  instead of hinges  190 . A single or plurality of specimen channels  140  may, for example, be formed as grooves within cassette base  180 . Such specimen channels may provide cavities by which a single or plurality of biopsy specimens  45  may be captured within cassette  130  upon closure of cassette lid  170 . The cassette  130  may allow biopsy specimens  45  to be positioned between the x-ray source  60  and ancillary digital image receptor  70  within beam  120 , thereby allowing expeditious and direct biopsy image processing for instant production of specimen radiographs within the procedure room via a computer control monitor with consequent benefits heretofore described. 
     FIGS. 12 and 13  illustrate one example of one means by which cassette  130  may be removably attached to ancillary digital receptor  70 . In this example, flanges  200  may be used to removably associate cassette  130  with ancillary digital image receptor face  150 . Other means to removably associate cassette  130  with the ancillary digital image receptor face  150  may comprise, but are not limited to, hook and loop fasteners, contact adhesives, magnets, tongue and groove connections, mechanical fasteners, and other similar or suitable means. 
     FIGS. 14 and 15  illustrate an example of another exemplary embodiment wherein the x-ray source  60  is provided with a means to be rotatably connected about a longitudinal axis to foundation  80 , whereby the x-ray source beam may be rotationally displaced from a working biopsy corridor beam axis  110  to position  120 . In this example, ancillary digital image receptor  70  may be rigidly or adjustably associated with digital imaging receptor  40  or with a convenient point on foundation  80 . Support means for x-ray source  60  may allow selective positioning of x-ray beam axis  120  so as to be normal to the ancillary digital image receptor face  150  shown in  FIGS. 12 and 13  in this exemplary embodiment. 
   Other embodiments include, but are not limited to, means of rotationally and/or laterally displacing the x-ray source about or relative to any axis or axes to provide sufficient displacement of an x-ray source beam from a working biopsy corridor beam axis  110  to allow unobstructed x-ray source illumination of a collected biopsy specimen  45  contained within a specimen cassette  130  associated with an ancillary digital image receptor  70 . It should be further noted that ancillary digital image receptor  70  may be fixedly or removably attached to a movable and adjustable support means (e.g., a cart, etc.) separate from (but in a suitable working vicinity of) a foundation  80  in some exemplary embodiments. 
     FIGS. 16 and 17  illustrate an additional embodiment, which includes a means for laterally and/or rotationally displacing an x-ray source  60 , as heretofore taught, in concert with similar means for laterally and/or rotationally displacing a digital imaging receptor  40  to allow sufficient displacement of a radiation beam axis  120  from a working biopsy corridor  110 , thereby allowing direct use of the digital imaging receptor  40  and eliminating the need for an ancillary digital image receptor  70 . This latter embodiment may provide a means for capturing and stabilizing a breast by a breast support plate  160 , which may be separately connected to foundation  80 , allowing independent use and free movement of the digital imaging receptor  40 . Furthermore, this exemplary embodiment may include a biopsy specimen cassette  130  that may be fixedly or removably associated with digital imaging receptor  40  in a manner similarly taught heretofore. 
   While certain exemplary embodiments of the present invention are described in detail above, the scope of the invention is not to be considered limited by such disclosure, and modifications are possible without departing from the spirit of the invention as evidenced by the following claims.