DOI:10.2214/AJR.05.0422
AJR 2006; 187:339-344
© American Roentgen Ray Society
Specimen Radiography in Confirmation of MRI-Guided Needle Localization and Surgical Excision of Breast Lesions
Basak Erguvan-Dogan1,
Gary J. Whitman1,
Victoria A. Nguyen1,
Mark J. Dryden1,
R. Jason Stafford2,
John Hazle2,
Krista R. McAlee2,
Michael J. Phelps1,
Mary F. Ice1,
Henry M. Kuerer3 and
Lavinia P. Middleton4
1 Department of Diagnostic Radiology, The University of Texas M. D. Anderson
Cancer Center, 1515 Holcombe Blvd., Unit 1350, Houston, TX 77230.
2 Department of Imaging Physics, The University of Texas M. D. Anderson Cancer
Center, Houston, TX 77230.
3 Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer
Center, Houston, TX 77230.
4 Department of Pathology, The University of Texas M. D. Anderson Cancer Center,
Houston, TX 77230.
Received March 18, 2005;
accepted after revision June 7, 2005.
Address correspondence to B. Erguvan-Dogan
(basakerguvan{at}yahoo.com).
Abstract
OBJECTIVE. Confirmation of lesion retrieval after MRI-guided needle
localization and surgical excision of breast lesions are difficult because the
targeted lesion is not enhanced ex vivo. The aim of this study was to
determine the feasibility of using specimen radiography to verify lesion
removal after MRI-guided needle localization and surgical excision.
CONCLUSION. To our knowledge, our study was the first to examine the
use of specimen radiography in the localization and excision of breast
lesions. Specimen radiography is a reliable, cost-effective alternative to
repeated dynamic contrast-enhanced MRI for confirming lesion removal after
surgery. Specimen radiography has the additional advantage of facilitating
immediate assessment of surgical margins.
Keywords: breast cancer • mammography • MRI • specimen radiography
Introduction
Dynamic contrast-enhanced MRI of the breast is becoming increasingly useful
in the detection, diagnosis, and management of breast cancer. For lesions that
cannot be detected with other techniques, MRI-guided interventional
procedures, such as needle localization and core biopsy, facilitate
histopathologic analysis. MRI-guided needle localization and excisional biopsy
is a well-recognized technique used in a growing number of practices
[1-8].
However, it is difficult to confirm removal of the targeted lesion, because
enhancement of the lesion diminishes over time and does not occur ex vivo.
Specimen radiography may be performed with different methods at various
institutions [9,
10]. An especially successful
method previously described entails imaging the entire biopsy specimen,
slicing the specimen into thin sections, and acquiring a second radiograph of
the sections [9]. This
technique allows 3D assessment of surgical margins and confirmation of removal
of the targeted lesion. Specimen radiography has been deemed especially
effective for patients undergoing limited surgery who need immediate
intraoperative assessment [9].
We hypothesized that specimen radiography may be useful in verifying that the
targeted lesion has been excised after MRI-guided needle localization and
excisional biopsy. To test our hypothesis, we studied the feasibility of using
two-view specimen radiography to confirm removal of targeted lesions after
MRI-guided needle localization and excision.
Materials and Methods
We retrospectively reviewed charts, dynamic contrast-enhanced MR images of
the breast, MRI-guided needle localization procedures, and specimen
radiographs of patients who had undergone MRI-guided needle localization and
excisional biopsy at a large academic institution. Owing to the
nonexperimental and retrospective nature of the study, informed consent was
not obtained from the patients. The institutional review board approved a
waiver of informed consent.
Review of medical records provided patient demographics, initial
indications for dynamic contrast-enhanced MRI studies of the breast and
MRI-guided needle localization procedures, types of surgery, and the outcome
of patient follow-up. Two breast radiologists experienced in interpreting
breast MR images and breast specimen radiographs reviewed the MRI-guided
needle localization procedures and specimen radiographs. An experienced breast
pathologist reviewed the pathology specimens.
Patient Characteristics and Indications for Dynamic Contrast-Enhanced Breast MRI
Ten patients had undergone MRI-guided needle localization and excisional
biopsy for 12 breast lesions. Eleven lesions were mammographically and
sonographically occult; one lesion was seen only on the craniocaudal view.
Indications for MRI-guided needle localization and excision were a history of
ipsilateral or contralateral breast cancer and suspicious enhancement on MRI
(n = 4), high genetic risk of breast cancer and a suspicious
enhancing lesion (n = 3), newly diagnosed stage I breast cancer and
ipsilateral enhancement suspicious for multicentric disease (n = 2),
and occult primary tumor presenting as axillary metastasis (n = 1).
The American College of Radiology BI-RADS—MRI Lexicon was used to
classify the morphologic and dynamic characteristics of the lesions
[11].
MRI-Guided Needle Localization Technique
All MRI-guided needle localization procedures were performed with a 1.5-T
MRI scanner (Signa, GE Healthcare). For MRI-guided needle localization
procedures, patients were positioned prone in a breast array coil with a
fenestrated grid localizing system applying moderate to slight compression,
and a fiducial marker was placed at the approximate entry site. After a
localizing sequence was obtained, a limited sagittal dynamic 3D fast spoiled
gradient-recalled echo study of the region of the lesion was performed
immediately after rapid IV bolus infusion of 0.1 mmol/kg gadopentetate
dimeglumine (Magnevist, Schering) at 3 mL/s with a power injector (Spectris MR
injector, Medrad).
On review of the images on a workstation, a cursor was placed over the
enhancing lesion on the monitor, and its distance from the lateral skin
surface and the fiducial marker was determined by manual scrolling through
sequential sagittal slices. An MR-compatible 20-gauge needle (MReye modified
disposable Kopans spring hook localization needle, Cook) was used for lesion
localization. An axial 3D fast imaging employing steady-state aquisition
(FIESTA) sequence was obtained to verify the location of the needle, and depth
adjustments were made if necessary. The hookwire was then deployed, and FIESTA
scanning in the axial and sagittal planes was repeated to verify wire
placement. A diagram outlining the procedure was drawn, and the approach was
discussed with the surgeon in each case. The diagrams and representative films
were reviewed with the surgeon before surgery. The surgeon excised a small
amount of breast tissue that contained the hookwire and the lesion.
Specimen Radiography
After the targeted lesion was excised, the specimen margins were inked with
six colors, each color indicating separate margins for histopathologic
evaluation. Slices 0.3-0.5 cm thick were radiographed with a dedicated
specimen radiography unit (Specimen Radiography System Model MX-20 Digital,
Faxitron) at 25 kVp and 1.5-minute exposure time. The radiologist viewed the
specimen radiographs and consulted with the pathologist and the surgeon while
the patient was in the operating room. The integrity of the hookwire was
assessed with whole-specimen radiography. Attention was also directed at
identifying a discrete lesion and evaluating margin status. The findings on
specimen radiography were used to guide the pathologist. When necessary,
additional margins were obtained during surgery. In four cases, MRI was
repeated 2 weeks after surgery to confirm successful excision of the targeted
lesion.
For the purposes of this study, two experienced breast imagers
retrospectively reviewed the specimen radiographs of all patients. On
sliced-specimen radiography, the morphologic features of the lesion were
compared with those seen on MRI. The morphologic criteria were those described
for mammography and MRI in the BI-RADS lexicon
[11]. The findings on specimen
radiography were correlated with the histopathologic findings.
Results
Final pathologic analysis revealed five (42%) of the lesions were malignant
and seven (58%) were benign. Mean lesion size on MR images was 1 cm, ranging
from 0.5 to 2.5 cm. Mean lesion size on specimen radiographs was 0.9 cm,
ranging from 0.4 to 2.2 cm. Mean lesion size at final histopathologic analysis
was 1.1 cm, ranging from 0.1 to 2.6 cm. Two benign lesions that did not show
abnormalities on specimen radiographs were fibrocystic disease associated with
benign epithelial hyperplasia. In one case in which specimen radiography
revealed fibroadenoma associated with a 0.1-cm focus of ductal carcinoma in
situ, findings on MRI 3 weeks after surgery showed no additional or residual
suspicious enhancement. Histopathologic results are summarized in
Table 1.
Whole-specimen assessment with specimen radiography showed an abnormality
in five (42%) of 12 lesions. Three of these lesions were malignant and two
were benign. In the three cases of malignancy, findings at margin assessment
on whole-specimen radiography were concordant with those of the final
histopathologic analysis. Integrity of the localizing wire was assessed on
whole-specimen radiography, and all of the localization wires were intact. In
all cases, the hookwire was seen inside or within 2 mm of the abnormality
detected on whole-specimen radiography and therefore was a marker for
identifying the targeted lesion.
Sliced-specimen radiography was performed in 11 of 12 cases. In 9 (82%) of
11 cases in which sliced-specimen radiographs were obtained, an abnormality
similar to that seen on dynamic contrast-enhanced breast MRI was identified.
In all five malignant cases, sliced-specimen radiographs showed the lesion in
question and helped the pathologist to correctly identify the lesion (Figs.
1A,
1B,
1C,
1D, and
1E). In the one case in which
only whole-specimen radiography was performed, benign epithelial proliferation
and fibrocystic changes were found at histopathologic analysis. On
sliced-specimen radiography in the cases of malignant lesions, four malignant
lesions were associated with negative margins, and one invasive ductal cancer
had positive margins (Figs. 2A,
2B,
2C,
2D, and
2E). In all malignant lesions,
sliced-specimen radiographic findings were concordant with the final
pathologic assessment of the margins.
View larger version (4K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A —50-year-old woman who underwent evaluation of questionable
density in outer aspect of left breast visible only on craniocaudal
mammographic views and not identified sonographically. Sagittal
contrast-enhanced dynamic MR image of breast in maximum slope in first minute
after contrast injection (TR/TE, 9/4; slice thickness, 4.0 mm; interslice gap,
4.0 mm; field of view, 22 cm) shows 9-mm lobulated mass (arrow) in
upper outer aspect of left breast. Results of dynamic time-intensity analysis
were consistent with findings at fast initial enhancement and delayed plateau
(not shown).
|
|
View larger version (5K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B —50-year-old woman who underwent evaluation of questionable
density in outer aspect of left breast visible only on craniocaudal
mammographic views and not identified sonographically. Axial 3D fast imaging
employing steady-state acquisition (FIESTA) image of breast (TR/TE, 4/1; slice
thickness, 5.0 mm; interslice gap, 5.0 mm, matrix size, 256 x 256; field
of view,16 cm) after insertion of needle shows needle (white arrows)
localizing region of targeted lesion according to x, y, and
z coordinates and anatomic landmarks (not shown). Changes associated
with injection of local anesthesia (black arrows) at skin entry are
evident.
|
|
View larger version (2K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C —50-year-old woman who underwent evaluation of questionable
density in outer aspect of left breast visible only on craniocaudal
mammographic views and not identified sonographically. Whole-specimen
radiograph shows targeted lesion at thickened segment (arrows) of
intact hookwire. S = superior, L = lateral.
|
|
View larger version (2K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1D —50-year-old woman who underwent evaluation of questionable
density in outer aspect of left breast visible only on craniocaudal
mammographic views and not identified sonographically. Sliced-specimen
radiograph shows irregular, spiculated mass (arrows) excised with
acceptable surgical margins. Image shows only sections of sliced-specimen
radiograph that contain excised lesion and surrounding margins. All specimen
margins are clear of tumor. A = anterior, P = posterior, M = medial.
|
|
View larger version (173K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1E —50-year-old woman who underwent evaluation of questionable
density in outer aspect of left breast visible only on craniocaudal
mammographic views and not identified sonographically. Histopathologic image
shows moderately differentiated invasive ductal carcinoma (arrow) and
intermediate-grade ductal carcinoma in situ (arrowhead) infiltrating
around adenosis. Tumor measured 0.9 cm; minimum 1-cm negativity of all margins
was verified. (H and E, x100)
|
|
View larger version (5K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A —45-year-old woman with history of cancer of left breast and
segmental mastectomy who underwent evaluation of palpable area in 6-o'clock
position of left breast. Mammographic and sonographic findings were normal.
Sagittal contrast-enhanced dynamic MR image obtained in maximum slope in first
minute after contrast injection (TR/TE, 9/4; slice thickness, 4.0 mm;
interslice gap, 4.0 mm; field of view, 22 cm) shows spiculated mass
(arrow) with heterogeneous enhancement in left breast suspicious for
malignancy according to morphologic findings. Results of dynamic
time-intensity curve analysis (not shown), which is also suspicious for
malignancy, were consistent with rapid wash-in and subsequent early
washout.
|
|
View larger version (5K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B —45-year-old woman with history of cancer of left breast and
segmental mastectomy who underwent evaluation of palpable area in 6-o'clock
position of left breast. Mammographic and sonographic findings were normal.
Axial 3D fast imaging employing steady-state acquisition (FIESTA) image
(TR/TE, 4/1; slice thickness, 5.0 mm, interslice gap, 5.0 mm; matrix size, 256
x 256; field of view, 16 cm) shows needle (arrows) localizing
region of targeted lesion.
|
|
View larger version (2K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2C —45-year-old woman with history of cancer of left breast and
segmental mastectomy who underwent evaluation of palpable area in 6-o'clock
position of left breast. Mammographic and sonographic findings were normal.
Whole-specimen radiograph shows mass (arrows) with adjacent intact
hookwire at periphery of specimen. L = lateral, S = superior, I = inferior, m
= medial.
|
|
View larger version (1K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2D —45-year-old woman with history of cancer of left breast and
segmental mastectomy who underwent evaluation of palpable area in 6-o'clock
position of left breast. Mammographic and sonographic findings were normal.
Sliced-specimen radiograph shows dense oval mass (arrows) with
inconspicuous margins at superior lateral margin of excised tissue sample.
Markers show 3D orientation to specimen. Markers indicating medial and lateral
margins are not shown. P = posterior, S = superior, A = anterior.
|
|
View larger version (164K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2E —45-year-old woman with history of cancer of left breast and
segmental mastectomy who underwent evaluation of palpable area in 6-o'clock
position of left breast. Mammographic and sonographic findings were normal.
Photomicrograph shows cauterized invasive and in situ carcinoma involving
inked lateral margin (arrows) of resection. Additional excised tissue
had evidence of malignancy. At mastectomy 6 weeks after this image was
obtained, no residual tumor was identified in mastectomy specimen. (H and E,
x100)
|
|
Of the five patients with malignant lesions, two were treated by
mastectomy; one of these patients underwent axillary lymph node dissection and
the other, sentinel lymph node biopsy. Two patients were treated with
segmental mastectomy and sentinel lymph node dissection. One patient, who had
a single 0.7-cm focus of ductal carcinoma in situ, underwent no additional
surgery. All five patients with malignant disease underwent adjuvant
chemotherapy, and four patients underwent postoperative radiation therapy. The
patient with atypical ductal hyperplasia bordering on ductal carcinoma in situ
was treated by wide excision with negative findings at the surgical margins.
All patients were free of disease 7-27 months after MRI-guided needle
localization and surgical excision.
Discussion
Specimen radiography is routinely used after mammographically guided needle
localization and excision. Specimen radiography is also commonly used after
sonographically guided needle localization and surgical excision, even though
the targeted lesion may be mammographically occult. Another method of
verification of lesion removal after sonographically guided needle
localization and excision is specimen sonography. Specimen sonography,
however, requires an expert sonographer, and margin assessment is difficult
[12,
13]. Although none of the
lesions evaluated in our study was seen on two-view mammography or sonography,
specimen radiography revealed an abnormality in most (82%) of the cases.
Radiographic margin assessment based on the two-view specimen radiographic
findings also was correct.
All malignant lesions were correctly identified with two-view specimen
radiography. A possible explanation for this condition may be that overlapping
breast parenchyma is removed during ex vivo radiographic evaluation of the
lesion. This theory is further supported by the fact that a higher percentage
(82%) of the lesions was visualized on sliced-specimen radiography than on
whole-specimen radiography (42%).
Identification of diffuse processes such as fibrocystic changes within the
parenchyma with specimen radiography was less successful than identification
of 3D masses. In our study, all of the detected cancers were ductal in origin.
On the basis of our results with diffuse benign processes, evaluation of
ill-defined malignant lesions, such as invasive lobular cancer, may be
difficult with specimen radiography.
An important advantage of specimen radiography is identification of
fractured localization wires after excisional biopsy. Specimen radiography
allows removal of wire fragments before patients leave the operating room.
Morris et al. [2] described two
fractured localization wires, which were detected on follow-up mammograms in a
series of 101 patients undergoing MRI-guided needle localization. In our
study, specimen radiography helped verify removal of all hookwires after
MRI-guided needle localization and excision.
Our results suggest that specimen radiography is helpful after MRI-guided
needle localization and excisional biopsy. To our knowledge, this study was
the first to examine the use of specimen radiography in this setting. A
limitation of our study is the small number of cases. Larger studies are
necessary for assessment of the use of specimen radiography after MRI-guided
needle localization and excision of otherwise occult lesions. Another
limitation is the lack of diffusely infiltrating cancers, which are difficult
to identify on radiography. Specimen radiography is a reliable, cost-effective
alternative to repeated dynamic contrast-enhanced MRI in the confirmation of
lesion removal after surgery. Specimen radiography has the additional
advantage of enabling immediate assessment of surgical margins. Further work
in this area might include placement of a radiographically visible marker clip
within the lesion to aid in identifying the lesion in question on
sliced-specimen radiography and on in vitro specimen MR spectroscopy.
Acknowledgments
We thank Dawn Chalaire for editing the manuscript; Joe Zhou and Michelle
Garcia for technical assistance; and Barbara Almarez Mahinda for secretarial
assistance.
References
- Prat X, Sittek H, Grosse A, et al. European quadricentric
evaluation of a breast MR biopsy and localization device: technical
improvements based on phase-I evaluation. Eur Radiol2002; 12:1720
-1727[CrossRef][Medline]
- Morris EA, Liberman L, Dershaw DD, et al. Preoperative MR
imaging-guided needle localization of breast lesions.
AJR 2002; 178:1211
-1220[Abstract/Free Full Text]
- Schneider E, Rohling KW, Schnall MD, et al. An apparatus for
MR-guided breast lesion localization and core biopsy: design and preliminary
results. J Magn Reson Imaging 2001;14
: 243-253[CrossRef][Medline]
- Lo LD, Orel SG, Schnall MD. MR imaging-guided interventions in the
breast. Magn Reson Imaging Clin N Am2001; 9:373
-380[Medline]
- Helbich TH. Localization and biopsy of breast lesions by magnetic
resonance imaging guidance. J Magn Reson Imaging2001; 13:903
-911[CrossRef][Medline]
- Daniel BL, Birdwell RL, Ikeda DM, et al. Breast lesion
localization: a freehand, interactive MR imaging-guided technique.
Radiology 1998;207
: 455-463[Abstract/Free Full Text]
- Kuhl CK, Elevelt A, Leutner CC, et al. Interventional breast MR
imaging: clinical use of a stereotactic localization and biopsy device.
Radiology 1997;204
: 667-675[Abstract/Free Full Text]
- Orel SG, Schnall MD, Newman RW, et al. MR imaging-guided
localization and biopsy of breast lesions: initial experience.
Radiology 1994;193
: 97-102[Abstract/Free Full Text]
- Chagpar A, Yen T, Sahin A, et al. Intraoperative margin assessment
reduces re-excision rates in patients with ductal carcinoma in situ treated
with breast-conserving surgery. Am J Surg2003; 186:371
-377[CrossRef][Medline]
- McCormick JT, Keleher AJ, Tikhomirov VB, Budway RJ, Caushaj PF.
Analysis of the use of specimen mammography in breast conservation therapy.
Am J Surg 2004;188
: 433-436[CrossRef][Medline]
- American College of Radiology. Breast imaging reporting
and data system atlas (BI-RADS atlas). Reston, VA: American
College of Radiology, 2003
- Fornage BD, Ross MI, Singletary SE, Paulus DD. Localization of
impalpable breast masses: value of sonography in the operating room and
scanning of excised specimens. AJR 1994;163
: 569-573[Abstract/Free Full Text]
- Frenna TH, Meyer JE, Sonnenfeld MR. US of breast biopsy specimens.
Radiology 1994;190
: 573[Abstract/Free Full Text]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Top
Abstract
Introduction
