| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Breast Imaging Section, Department of Radiology, Memorial Sloan-Kettering
Cancer Center, 1275 York Ave., New York, NY 10021.
2 Physics Section, Department of Radiology, Memorial Sloan-Kettering Cancer
Center, New York, NY 10021.
Received August 6, 2001;
accepted after revision October 23, 2001.
Supported by a grant from the Susan B. Komen Foundation.
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MATERIALS AND METHODS. Retrospective review revealed 101 consecutive breast lesions that had preoperative MR imaging—guided needle localization with commercially available equipment, including a 1.5-T magnet with a breast surface coil, a dedicated biopsy compression device, and MR imaging—compatible hookwires. Imaging studies and medical records were reviewed.
RESULTS. Histologic findings in these 101 lesions were carcinoma in 31 (30.7%), high-risk lesions (atypical ductal hyperplasia or lobular carcinoma in situ) in nine (8.9%), and benign lesions in 61 (60.4%). Fifteen (48.4%) of 31 carcinomas were ductal carcinoma in situ, and 16 (51.6%) were infiltrating carcinoma (size range, 0.1-2.0 cm; median, 1.2 cm). Carcinoma was found in 16 (45.7%) of 35 lesions detected in women with synchronous cancer, 10 (32.3%) of 31 lesions detected on MR imaging for problem solving, and five (14.3%) of 35 lesions detected on MR screening. The time range to perform MR imaging—guided localization was 15-59 min (median time, 31 min). Complications encountered in three cases were retained wire fragments in two and breakage of the wire tip in one.
CONCLUSION. MR imaging—guided needle localization can be performed quickly and safely with commercially available equipment. The positive predictive value of MR imaging—guided needle localization (30.7%) was comparable to that reported for mammographically guided needle localization and was highest in women with synchronous breast cancer.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MR imaging—guided localization poses unique challenges [2]. Except in open magnets, the patient must be removed from the magnet for the radiologist to gain access to the breast for performing the localization procedure. Because MR imaging is usually performed with the patient prone, the lateral breast is accessible, but access to the medial breast may be more difficult. After contrast injection, lesion conspicuity diminishes over time because of the transient nature of contrast enhancement. For MR imaging—guided surgical biopsy, confirmation of lesion retrieval is difficult because the lesion does not enhance ex vivo. Few data address MR imaging—guided needle localization for surgical excision [1,2,3,4,5]. Our study reports the technique and results of MR imaging—guided needle localization for surgical biopsy using commercially available equipment.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The first 22 lesions had localization under an institutional review board—approved protocol that required the MR imaging lesion to have a mammographic correlate; in these lesions, the decision to biopsy was already made on the basis of the mammographic findings. Of the subsequent 79 lesions, one had a mammographic correlate, one had both a mammographic and a sonographic correlate, and one had a sonographic correlate but no mammographic correlate. In these three women, MR imaging—guided localization was performed because of the existence of synchronous ipsilateral lesions identified on MR imaging only. Therefore, among 101 lesions in this study, MR guidance was essential for localization in 76 (75.2%).
Breast MR Imaging: Indications and Technique
Of these 69 women, 66 had breast MR imaging before the date of biopsy at
our facility and three, at outside facilities. Twenty-four (35%) had MR
imaging performed for high-risk screening, including a positive family
history, biopsy-proven diagnosis of atypical ductal hyperplasia, lobular
carcinoma in situ, ductal carcinoma in situ (DCIS), or prior invasive breast
cancer. MR imaging was performed for problem solving in 23 (33%), including
questionable findings on mammography, sonography, or at physical examination,
or occult carcinoma consistent with breast primary in an axillary lymph node.
The remaining 22 (32%) had MR imaging performed for staging of breast
cancer.
At our institution, diagnostic MR imaging was performed with the patient prone in a 1.5-T commercially available system (Signa; General Electric Medical Systems, Milwaukee, WI), using a dedicated surface breast coil (MRI Devices, Waukesha, WI). Our imaging sequence included a localizing sequence followed by a sagittal fat-suppressed T2-weighted sequence (TR/TE, 4000/85). A T1-weighted three-dimensional fat-suppressed fast spoiled gradient-recalled sequence (17/2.4; flip angle, 35°; bandwidth, 31.25 kHz) was then performed before and three times after a rapid bolus injection of 0.1 mmol/L of gadopentetate dimeglumine (Magnevist; Berlex, Wayne, NJ) per kilogram of body weight. Contrast material was administered as a rapid bolus injection through an indwelling IV catheter. Image acquisition started immediately after contrast agent and saline bolus injection. Images were obtained sagittally, for an acquisition time per volumetric acquisition of less than 2 min each. Total imaging time per breast, including three enhanced acquisitions, was approximately 15 min.
Section thickness was 2 mm without gap, using a matrix of 256 x 192 and field of view of 16-18 cm. Frequency was in the anteroposterior direction. After examination, the unenhanced images were subtracted from the first enhanced images on a pixel-by-pixel basis.
Interpretation of Breast MR Images
MR images were interpreted on hard-copy film and later on soft copy using a
PACS (picture arching and communication system) (General Electric Medical
Systems) that allowed manual window settings and optimization of parameters.
MR images were interpreted in conjunction with other breast images, including
mammograms and sonograms when available.
Level of suspicion was reported on a scale of 0-5, identical to that in the lesion-assessment categories used in the Breast Imaging Reporting and Data System (BI-RADS) [6]. Numeric categories were the following: 0, needs additional imaging evaluation; 1, normal; 2, benign; 3, probably benign, recommend 6-month follow-up MR imaging; 4, suspicious; or 5, highly suggestive of malignancy. Lesions that were considered suspicious or highly suggestive of malignancy had morphologic features that included spiculated or irregular margins, heterogeneous or rim enhancement, or clumped enhancement in a linear or segmental distribution [7,8,9,10,11]. Tiny (1 mm) foci of enhancement or stippled enhancement was a morphologic feature that did not prompt biopsy. Similarly, masses with smooth borders and homogeneous enhancement were generally not considered suspicious. Classification was based primarily on lesion morphology; however, kinetic features were visually assessed on the three enhanced image acquisitions [7], with quantitative kinetic curves generated in specific cases at the request of the interpreting radiologist, usually for lesions with morphologic features considered probably benign [12, 13].
For lesions interpreted as suspicious or highly suggestive of malignancy on MR imaging, correlative sonography was often performed to determine if the lesion was sonographically evident and, thereby amenable to tissue sampling under sonographic guidance. If the lesion was not seen on sonography, MR imaging—guided localization was recommended. If the lesion was reliably visualized on sonography or mammography, biopsy was usually performed with the guidance of those imaging modalities.
MR Imaging—Guided Needle Localization Technique
The localization was performed with the patient positioned prone with both
breasts in a dedicated surface breast coil (Fig.
1A,1B,1C,1D).
The breast undergoing localization was placed in a dedicated biopsy
compression device using a grid-localizing system that was a commercially
available model (Biopsy-System No. NMR NI 160, MRI Devices) (Fig.
1A,1B,1C,1D)
or a slightly modified design of the commercially available model. The medial
aspect of the breast was first positioned flush against a compression plate. A
lateral grid was then firmly adjusted to fully compress and immobilize the
breast. A vitamin E capsule was used as a fiducial marker and was taped to the
lateral grid over the expected lesion site, on the basis of review of the
diagnostic MR images.
|
|
|
|
An axial localizing T1-weighted sequence was obtained, and the volume of interest was selected to include the compression device and the vitamin E marker that was taped to the lateral grid (Fig. 2A,2B,2C,2D,2E,2F). Gadopentetate dimeglumine, 0.1 mmol/L per kilogram of body weight, was then injected IV as a rapid bolus injection through an indwelling IV catheter. No unenhanced image was obtained. Image acquisition started immediately after contrast injection for the diagnostic examination with images obtained in the sagittal plane. Time of acquisition, usually less than 1 min, varied, depending on the size of the breast and area covered. Because the entire breast frequently was not imaged during a localization procedure, acquisition time was shorter than that for the diagnostic examination.
|
|
|
|
|
|
Images were reviewed at the workstation. A cursor was placed over the lesion on the monitor, and its relationship to the skin surface and the vitamin E marker was determined by manually scrolling through sequential sagittal slices. The grid of the compression device was evident as low-signal intensity lines at the skin surface due to pressure indentation; the plastic of the compression device was not visible on MR imaging. The vitamin E capsule was identified as an area of high signal intensity at the skin surface (Fig. 2A,2B,2C,2D,2E,2F). The skin entry site was determined on the basis of visual assessment of the location of the lesion with respect to the grid lines, using the vitamin E capsule as a guide. The depth of the lesion from the skin surface was calculated as the difference between the depth of the skin surface and the depth of the sagittal slice containing the lesion.
After calculating the entrance site and lesion depth, we withdrew the patient from the magnet. A mark was made on the skin overlying the lesion, and the skin was cleansed with alcohol and anesthetized with 1-2 mL of 1% lidocaine HCl (Xy-locaine; Astra USA, Westborough, MA). A needle guide (Biopsy-System No. NMR NI 160, MRI Devices) was inserted into the grid hole overlying the anesthetized area. The needle guides were manufactured to have 18- or 20-gauge holes to accommodate various needle sizes. The needle guide was used to anchor and stabilize the needle and to allow insertion of the needle in a straight perpendicular fashion, reducing needle angulation during insertion. The MR-compatible needle and hookwire (Tumor Localizer, 18 or 20 gauge, Daum Medical, Schwerin, Germany; or MRI Breast Lesion Marking System, 20 gauge, E-Z-EM, Westbury, NY) were then placed in the hole of the needle guide closest to the marking on the skin. We inserted the needle to the desired depth, taking into account the 1.5-cm thickness of the needle guide.
Sagittal contrast-enhanced T1-weighted images were then obtained to document the location of the needle, with the desired depth of the tip optimally positioned 0.5-1.0 cm deep in relation to the lesion. The needle was evident as a low-signal-intensity structure with adjacent susceptibility artifact (Fig. 2A,2B,2C,2D,2E,2F). Visualization of the target lesion might have been compromised by needle artifact on these images, especially if the lesion was small. Surrounding anatomic landmarks often were useful when verifying lesion depth. Also, the lesion may have been less conspicuous because of washout of contrast material. However, identification of the target site was generally not a problem because we could localize the lesion relative to the vitamin E marker, the location of the tip relative to the desired depth, and the analysis of surrounding landmarks. If the needle was too deep or too superficial, adjustments were made. When the needle tip was in good position, the wire was deployed by advancing the wire to the mark indicating that the tip had emerged from the needle. We then removed the needle, leaving the wire in place, and a final series of T1-weighted contrast-enhanced images was obtained to document wire position.
For medial lesions, the patient was often positioned in a prone oblique position rather than in straight prone position. For example, to localize a lesion in the medial left breast, we placed the left breast in the right breast coil, making the medial aspect of the left breast accessible.
After localization, a two-view mammogram was obtained so that the surgeon could see the location of the wire with respect to the nipple, the chest wall, and the remainder of the breast tissue. These films were labeled, a labeled diagram was drawn, and these were sent to surgery along with the patient.
Bilateral Localization
When bilateral localization was performed, one of two methods was used.
More often, after injection of contrast material, both breasts were imaged,
and the lesions in each breast were localized simultaneously. Alternatively,
we imaged and localized each breast lesion separately, allowing an adequate
passage of time (
20 min) after the initial contrast injection so that
background parenchymal enhancement did not obscure areas of suspicious
enhancement in the second breast when the patient was reinjected with contrast
material for the second localization.
Data Collection and Analysis
Breast MR images were reviewed to assess lesion size and location.
Mammograms and sonograms were reviewed to determine if the MR imaging finding
had a mammographic or sonographic correlate. Breast parenchymal density was
classified according to the American College of Radiology BI-RADS lexicon
[6] as class 1 (almost entirely
fat), class 2 (scattered fibroglandular densities), class 3 (heterogeneously
dense), or class 4 (extremely dense). Postoperative MR imaging was not
routinely performed during the study period but was ordered at the discretion
of the attending surgeon; these examinations were reviewed, when available, to
assess lesion retrieval.
The maximal diameter for each lesion was measured with electronic calipers at the PACS workstation. The median time to perform MR imaging—guided needle localization, from the begining of acquisition of the localizing MR images to completion of acquisition of the MR images obtained after deployment of the wire, was calculated for the first 50 lesions. In 90 lesions in which the relevant sequences were available in PACS for review, measurement was made of the distance between the depth of the lesion on the initial enhanced acquisition and the depth of the wire tip on the final image after deployment.
Medical records were reviewed to determine histologic findings and complications. The positive predictive value of MR imaging—guided needle localization was defined as the number of cancers found at MR imaging—guided needle localization divided by the total number of lesions that underwent MR imaging—guided needle localization. Imaging and histologic findings were considered concordant if the histologic findings provided a sufficient explanation for the imaging features [14]. Data were collected on a computerized spreadsheet (Excel; Microsoft, Redmond, WA). Statistical analysis was performed using statistics software (Epi Info; Centers for Disease Control, Atlanta, GA) using the chisquare and Fischer's exact tests.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Histologic Findings
MR imaging—guided needle localization yielded carcinoma in 31 lesions
(30.7%), high-risk lesions (atypical ductal hyperplasia or lobular carcinoma
in situ) in nine (8.9%), and benign findings in 61 (60.4%)
(Table 1). MR
imaging—guided needle localization yielded carcinoma in nine (37.5%) of
24 lesions that had mammographic correlates and in 22 (28.6%) of 77 lesions
without mammographic correlates (p = 0.57).
|
Histologic findings in 31 carcinomas were DCIS in 15 (48.4%) and infiltrating carcinoma in 16 (51.6%). The size range of infiltrating carcinoma was 0.1-2.0 cm (median, 1.2 cm). Among 16 infiltrating carcinomas, histology was infiltrating ductal carcinoma and DCIS in eight (50.0%), infiltrating lobular carcinoma in four (25.0%), infiltrating ductal and lobular carcinoma and DCIS in three (18.8%), and infiltrating ductal carcinoma in one (6.3%).
Positive Predictive Value in Patient Subgroups
Carcinoma was present in 16 (45.7%) of 35 lesions referred for MR
imaging—guided localization in women with synchronous cancer (Fig.
3A,3B,3C,3D),
10 (32.3%) of 31 lesions referred for MR imaging—guided localization in
women having MR imaging for problem solving (Fig.
4A,4B),
and five (14.2%) of 35 lesions referred for MR imaging—guided localizing
in women who had MR imaging for screening (Fig.
5A,5B,5C).
|
|
|
|
|
|
|
|
|
The positive predictive value of MR imaging—guided localization was significantly greater if the indication for the initial MR examination was synchronous cancer or problem solving rather than screening (26/66 = 39.4% vs 5/35 = 14.2%, p < 0.02). Among 16 carcinomas diagnosed on MR imaging—guided localization in women with synchronous cancer, the cancers that had MR imaging—guided localization were in the ipsilateral breast in 12 (in the same quadrant in 10 and in a different quadrant in two) and in the contralateral breast in four.
Procedure Time, Accuracy, and Complications
The time range to perform MR imaging—guided needle localization was
15-59 min (median, 31 min). The distance range between the depth of the wire
tip and the depth of the lesion was 0.0-3.4 cm (median, 1.0 cm). In 90 lesions
in which the distance could be determined, the distance between the depth of
the wire tip and the depth of the lesion was 1.0 cm or less in 48 lesions
(53.3%), 1.1-2.0 cm in 41 lesions (45.6%), and greater than 2.0 cm in one
lesion (1.1%). All lesions were positioned in the grid during the
localization.
Complications were encountered in three (2.9%) of 101 lesions. In one woman who had MR imaging—guided needle localization of a solitary unilateral lesion, the tip of the wire broke off in the breast during deployment, and this complication required placement of a second wire. The tip, which was immediately adjacent to the lesion site, was successfully removed at surgery. In two other patients, postoperative mammography showed a retained wire fragment adjacent to the benign biopsy site. The reason for wire breakage was unknown, but our surgeons anecdotally reported that the wires may not have been as strong as those used for mammographically guided needle localization, with a propensity to break when approached by cautery. No other complications were encountered.
Follow-Up
Surgical histology and imaging findings were considered concordant in all
cases. Specimen radiography, performed in 13 lesions with mammographic
correlates, confirmed lesion retrieval in all cases.
Among 101 lesion sites, 15 were not available for imaging follow-up because the patients had undergone ipsilateral mastectomies, because of ipsilateral cancer in 13 and as prophylactic procedures in two. Postoperative MR imaging data were available in 33 (38.4%) of the remaining 86 lesion sites, including 19 (34.5%) of 55 lesions that yielded benign findings and 14 (45.2%) of 31 lesions that yielded carcinoma. The time range from surgery to the first follow-up MR imaging was 1-24 months (median, 8 months).
Postoperative MR imaging of 33 lesion sites suggested that the lesion had been completely excised in 29 (87.9%), partly excised in three (9.1%), and missed in one (3.0%). In three lesions that yielded carcinoma at surgery, postoperative MR imaging confirmed partial excision of the lesion but raised the possibility of residual disease. These three lesions occurred in two women, both of whom had undergone MR imaging—guided needle localization of multiple synchronous lesions, yielding findings of DCIS with close margins. Subsequent reexcision, performed in both women, yielded DCIS in one (Fig. 6A,6B,6C,6D,6E) and benign findings in the other. In one patient who had MR imaging—guided localization of multiple synchronous lesions with findings of multifocal infiltrating lobular carcinoma with tumor at the margin, postoperative MR imaging suggested persistence of one of the lesions; subsequent MR imaging—guided needle localization and reexcision showed infiltrating lobular carcinoma in an intramammary lymph node (Fig. 7A,7B,7C).
|
|
|
|
|
|
|
|
Thirty-five lesion sites that did not undergo postoperative MR imaging or did not have subsequent mastectomy underwent postoperative mammography in a time range of 4-20 months (median, 9 months) after biopsy, showing no suspicious findings. Eighteen lesion sites were not imaged after surgery on mammography or MR imaging; however, all patients had stable clinical follow-up.
Canceled Procedures
During the period in which these 101 lesions underwent MR
imaging—guided localization, an additional five lesions scheduled for MR
imaging—guided needle localization were not visible on the day of the
procedure and hence were not localized. These five lesions occurred in five
women having an age range of 31-71 years (median, 57 years). All five women
still underwent MR imaging—guided localization of other persistent
suspicious lesions in the ipsilateral (n = 3) or contralateral
(n = 2) breast. Three of the five women had follow-up MR imaging
(range, 1-7 months; median, 4 months), which confirmed disappearance of the
lesion. Five months after attempted localization, one woman underwent
follow-up mammography that showed no suspicious findings. One month after the
date of MR imaging—guided localization, one patient underwent
prophylactic mastectomy of the ipsilateral breast, which showed no evidence of
carcinoma.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
The positive predictive value of MR imaging—guided needle localization was greatest in women with known synchronous cancer (45.7%), in whom MR imaging led to detection of multifocal disease warranting wider excision, multicentric disease requiring mastectomy, or otherwise unsuspected contralateral carcinoma [1, 16]. The availability of MR imaging—guided needle localization made it feasible to use MR imaging in a problem-solving capacity in a variety of scenarios, including questionable imaging or physical findings [17] or occult carcinoma in an axillary node [18, 19]. MR imaging—guided needle localization also enabled diagnosis of cancers detected on screening examinations in high-risk women [20, 21]. However, the positive predictive value of MR imaging—guided localization was greater if the indication for the initial MR imaging was for the extent of disease assessment in women with synchronous cancer (45.7%) or problem solving (32.3%) rather than for screening (14.3%).
We encountered several technical challenges on MR imaging—guided needle localization. Variation often occurred in the appearance of the lesion between the diagnostic MR imaging performed at our facility and the images obtained on the day of the localization procedure, perhaps because of difference in positioning, compression, or phase of the patient's menstrual cycle [22]. If the lesion was not present on the initial enhanced scan and the examination was technically adequate, as occurred in five (4.7%) of 106 lesions referred for MR imaging—guided needle localization during the study, the procedure was canceled and follow-up MR imaging was suggested. If the lesion is less conspicuous on the day of the localization procedure, administration of additional IV contrast material and reimaging may be of value. It may also be helpful to use adjacent landmarks, as are often used during mammographically guided needle localization of subtle lesions.
Posterior lesions can be difficult to visualize on MR imaging—guided needle localization. In these cases, positioning of the patient by mammography technologists improved visualization of the area of interest; their experience at positioning the breast for diagnostic mammography as well as in a variety of interventional breast procedures (including stereotactic biopsy with the patient prone) was most helpful. In our study, all lesions were successfully positioned in the grid. However, if a lesion could not be included in the grid because of an extreme posterior location, the radiologist could place the needle in the grid as close to the lesion as possible and confer with the surgeon; the surgeon could then excise the tissue posterior to the needle (extending from the wire toward the pectoral muscle), as is our practice for mammographically guided needle localizations of extremely posterior lesions.
Access to medial lesions may also be challenging. Because of the geometry of the particular type of breast coil used in our study, if the patient lies prone with her breast in the breast coil, the needle can be placed from her lateral side but not from her medial side. This placement is suboptimal for medial lesions because it requires that the needle and wire traverse a longer distance. The prone oblique position that we used for medial lesions with the breast in the contralateral coil is most successful on women who are healthy and relatively thin. Hip problems may make the oblique position less comfortable, and obesity may limit body access to the magnet in this position. The MR imaging technologist must be aware that the left breast is being imaged in the right breast coil so that the images can be properly acquired and annotated.
A potential problem with MR imaging—guided localizations relates to the fact that the wire is deployed with the breast in compression parallel to the direction of needle placement. This deployment creates an accordion effect. During compression, structures that are far apart are brought close together, and when compression is released, structures that are close together move farther apart [23]. Any error in the depth direction (parallel to the axis of needle placement) can therefore be exaggerated when compression is released. The accordion effect can be minimized by keeping compression to the minimum necessary to achieve immobilization. Use of adequate, but minimal, compression can also prevent impairment of contrast enhancement, which has been observed with compression that was overly vigorous [3].
Confirmation of lesion retrieval remains an issue for MR imaging—guided localization. Imaging—histologic correlation plays an important role in this procedure, as in breast biopsy with any method [14]. Creation of an MR imaging—compatible mammographically evident clip that can be placed after MR imaging—guided core biopsy would be useful, so that specimen radiography could document retrieval of the clip [24]. Postoperative MR imaging, which can distinguish postoperative changes from residual tumor, may be helpful [25, 26]. Postoperative MR imaging, performed in 33 lesion sites in this study, suggested that the lesion was completely excised in 29 (87.9%), partly excised in three (9.1%), and missed in one (3.0%). These results are within the range of 0-17.9% miss rates for mammographically guided needle localization reported in a review of the literature by Jackman and Marzoni [15]. The four lesions that were partly excised (n = 3) or missed (n = 1) in our study all occurred in women who had MR imaging—guided localization of multiple synchronous ipsilateral lesions, yielding carcinoma extending to or close to the margins. These findings are consistent with the results of Jackman and Marzoni, who reported that mammographically guided needle localization and surgical biopsy had a failure rate of 12% for patients with multiple ipsilateral lesions versus 1.6% for patients with single lesions (p = 0.001).
For individuals performing MR imaging—guided breast needle localization and biopsy procedures, several suggestions might be of value. Begin with lesions that have mammographic correlates so that lesion retrieval can be readily confirmed during the learning experience. Collaboration with individuals expert in MR imaging physics is invaluable. MR imaging technique should be standardized, maximizing comparability between the diagnostic MR images and the images obtained during the localization or biopsy procedure. If feasible, identify specific MR imaging technologists who will be involved in these procedures and include participation of mammography technologists experienced at breast localization and biopsy procedures. Perhaps postoperative MR imaging should be incorporated into the routine-follow-up of patients who have MR imaging—guided localization to ensure lesion retrieval if MR imaging—guided localization yields benign findings and to assess for residual tumor if MR imaging—guided localization reveals breast cancer; Frei et al. [26] have suggested that this imaging may best be performed approximately 1 month after surgery.
Although occult malignancies were detected with MR imaging and ultimately localized under MR imaging guidance, the impact of these diagnoses on patient outcome is unknown. The detection of synchronous contralateral cancer might improve patient survival if the index tumor is localized and small. Clearly, MR imaging detects additional tumors that evade detection by conventional methods; however, the clinical significance of subclinical tumor, particularly DCIS, identified only at MR imaging, is unknown. Detection of additional DCIS in a separate quadrant in a patient who would undergo breast conservation followed by radiation therapy may not affect patient outcome because the additional DCIS may be effectively treated by radiation. Beyond these issues, to our knowledge, cost-effectiveness of MR imaging—guided localization has not yet been assessed.
The capability to localize and biopsy is a necessary part of a breast MR imaging program. We present our results with MR imaging—guided localization using commercially available equipment to share the lessons we have learned from preliminary experience, to assist in the development and dissemination of this technology, and to help identify areas in need of further research. Ideal characteristics of the MR imaging localizing needle and wire combinations include "scoring" (1-cm marks on the needle shaft that can be used to adjust needle position), a readily visible mark on the wire that one can set to a specified position for deployment, a reinforced portion that the surgeon can identify intraoperatively, and sufficient strength to resist breakage or cutting. MR imaging—compatible core and vacuum-assisted biopsy systems should include compression devices to allow access to and immobilization of the entire breast, needle guides, and localizing markers. MR imaging—compatible biopsy equipment is being developed to meet these needs. This technology and work validating its use will help to realize the potential of breast MR imaging in breast cancer detection and treatment.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Gossmann, C. Bangard, M. Warm, R. K. Schmutzler, P. Mallmann, and K.-J. Lackner Real-time MR-guided Wire Localization of Breast Lesions by Using an Open 1.0-T Imager: Initial Experience Radiology, May 1, 2008; 247(2): 535 - 542. [Abstract] [Full Text] [PDF]
|
