| |
 |
Download PDF Version of this Article
Bookmark this Site
|
|
Archived Issues of Radiology Rounds
MGH Department of Radiology Website
|
| |
Percutaneous Image-Guided Breast Biopsy
|
| |
- Image-guided
biopsy is indicated for both palpable and non-palpable breast lesions
suspicious for malignancy and is a cost-effective procedure that
reduces the number of surgeries
- Ultrasound-guided
biopsy allows real-time imaging, can be performed without breast
compression, and is the preferred method if the lesion is detectable
with ultrasound
- Stereotactic (mammographic) biopsy is used primarily for microcalcifications and for masses not visible with ultrasound
- MRI-guided biopsy is used for suspicious areas of contrast enhancement that cannot be seen on ultrasound or mammography
|
Percutaneous
image-guided breast biopsies are rapid, minimally invasive procedures
that make surgery unnecessary for a large majority (70-80%) of patients
whose lesions will prove to be benign. The image-guided biopsies are
performed under local anesthetic with no need for conscious sedation
using a small incision that requires no stitches to close. The
procedures do not deform the breast and cause minimal to no scarring on
subsequent mammograms. Complications, such as hematoma and infection
are rare, occurring in less than 1 per 1000. Patients diagnosed with
breast cancer by image-guided biopsy will require fewer surgeries, on
average, than those diagnosed by surgical biopsy. Thus, percutaneous
image-guided breast biopsies are both medically preferable and
cost-effective and have largely replaced surgical biopsies for
pathologic diagnosis.
Image-guided biopsy is recommended
for almost all cases of suspected breast cancer (BI-RADS 4-5), whether
or not the patient is symptomatic or the lesion palpable.
|
|
Women who have palpable lesions not visible by imaging are biopsied
surgically. Because percutaneous biopsy requires that the patient have
normal coagulation rates, surgical biopsy may be considered in patients
taking coumadin to minimize their time off medication.
Even if imaging prior to intervention shows a very high likelihood of
malignancy, image-guided biopsy can provide useful information for
surgical planning. In addition to confirming the diagnosis, biopsy can
sometimes reveal multifocal (multiple sites within same quadrant) or
multicentric (multiple sites within different quadrants) carcinoma.
Knowing that the lesion is definitively a cancer allows the surgeon to
sample axillary nodes for metastasis at the time of definitive
excision. In addition, the likelihood of attaining clear margins at the
first operation after percutaneous diagnosis of cancer is 75-100%,
compared to 45-64% when a diagnosis has not been established, thereby
sparing additional surgery in a significant number of patients.
Percutaneous image-guided biopsy may be performed under ultrasound,
stereotactic, or MRI guidance. The selection of modality depends on the
imaging characteristics of the lesion. Some advantages and
disadvantages of the alternate procedures are listed in Table 1.
|
| Table 1. Advantages and Disadvantages of Percutaneous Breast Biopsy Methods |
Biopsy Method
|
Advantages |
Disadvantages |
| Ultrasound-guided |
Real-time visualization of biopsy needle
Accessibility of all areas of breast and axilla
Multidirectional sampling possible
Low cost
|
Can only be performed if lesion is sonographically evident
Difficulty in confirming lesion retrieval
|
| Stereotactic |
Can be used for almost all lesions visualized on mammograms
X-ray of biopsy specimen confirms that targeted lesion was sampled
|
No real-time visualization of biopsy needle
Discomfort from breast compression
Must have arms raised up; may not be possible for patients with limited shoulder movement
Must have adequate compressed breast thickness to allow biopsy
|
| MRI-guided |
Can be performed when lesions are visible on MRI but not on other modalities. |
Transient contrast enhancement may limit ability to see lesion
Difficult to confirm lesion retrieval
|
 |
Figure 1. Ultrasound-guided
biopsy of breast lesion. The diagnostic study (A) shows a solid lesion
(calipers) suspicious for cancer. An image during the biopsy (B)
shows the core biopsy needle (arrows) sampling the lesion.
|
|
Ultrasound-Guided Biopsy
|
|
|
Ultrasound
guidance is the method of choice for all patients when the lesion can
be visualized by this modality (Figure 1). This method is easiest for
both patient and operator because, unlike the other techniques, the
lesion can be can be sampled without breast compression while the
patient is reclining in the supine position. Under real-time imaging
guidance, a radiologist inserts a core biopsy needle into the lesion
and withdraws multiple samples. The sensitivity and specificity of this
procedure for detecting malignancy has been reported to be 97% and
100%, respectively.
|
|
A
radiographically visible clip, 1-2 mm in size, is sometimes placed
after the biopsy sample is removed to mark the site from which the
sample was taken in case further surgery is needed. Placement of a clip
is considered if the targeted lesion is <5 mm in size, because the
lesion remaining after biopsy may be too small to find by ultrasound. A
clip will also be placed if the patient is a likely candidate for
neoadjuvant therapy; that is if a lesion is ≥3 cm and the imaging
characteristics are highly suggestive of malignancy. In these cases,
chemotherapy may cause the tumor regression to the point where it is no
longer evident on imaging. The presence of a clip allows accurate
localization of the tumor at the time of surgical excision.
|
*MRI screening is only for patients with high familial risk factors. See When should breast MRI be used?
Radiology Rounds, October 2005
|
| Figure 2. Algorithm for the selection of the appropriate image-guided biopsy modality. |
|
Stereotactic (Mammographic) Biopsy
|
|
MRI-Guided Biopsy
|
Mammographic
calcifications, a potential sign of malignancy, are generally not
visible by ultrasound; for these lesions stereotactic biopsy is the
method of choice. For this procedure, the patient must lie prone
on a special table, which is elevated to allow access to the breast
from below. The breast is held in compression while stereotactic x-ray
images are taken, the 3-dimensional location of the lesion determined,
and the optimal path to the lesion calculated. A computer-guided needle
is inserted to the calculated position and a second pair of
stereotactic images confirms the position of the needle. Once the
lesion has been biopsied, radiographic demonstration of the originally
targeted lesion in the specimen confirms sampling validity. If the
target lesion is not present, the procedure can be repeated. In the
vast majority of cases, marker clips are placed immediately after
biopsy because the lesion may no longer be visible radiographically.
The sensitivity and specificity of stereotactic biopsy for detecting
malignancy has been reported to be 95% and 97%, respectively.
|
|
MRI-guided
biopsy is only used when suspicious lesions can be visualized with this
modality but not with mammography or ultrasound. The patient lies prone
with her breasts positioned in a dedicated breast MRI coil and
stabilized with moderate compression in a biopsy guidance grid. After a
localizing scan, the patient table is moved out of the bore of
the magnet to allow access to the breast. A biopsy sheath is inserted
into the calculated position of the lesion and a second scan confirms
the correct position of the sheath. The table is again moved out of the
magnet bore and a biopsy sample withdrawn with a vacuum assisted device
and an MRI-safe marker clip placed to denote the site of biopsy should
surgery be needed. A final scan of the biopsied region verifies the
location of the sampling site and marker clip. Reports of the technical
success rate range from 95-100%.The reported cancer yield is 20-55% in
the population who undergo this procedure.
|
 |
| Figure 3. MRI-guided
biopsy. The diagnostic MR image (A) demonstrates an area of abnormal
contrast enhancement (arrow). Mammogram following the biopsy (B)
shows the clips (arrows) placed to mark the biopsy site. |
|
Histological Concordance
Image-guided
biopsies are not considered complete until the result from histological
analysis is shown to be in agreement with the suspected radiologic
diagnosis. This process is known as establishing radiologic-pathologic
concordance. If the histological results do not agree with the
radiologic assessment (discordance), the lesion must be surgically
excised for pathologic certainty. In addition, if there are findings of
atypical ductal hyperplasia, lesion resection is warranted because
surgical findings may upgrade the lesion to ductal carcinoma in situ or
invasive carcinoma.
Scheduling and Patient Management
Once
identified as a candidate for percutaneous image-guided biopsy, the
patient meets with the Breast Imaging Nurse Coordinator, who will
explain the details of the upcoming procedure, answer the patient’s
questions, and coordinate a time for her biopsy. Alternatively, breast
biopsy procedures can be scheduled by calling 617-726-3094.
|
|
Further Information
For
further questions on percutaneous breast biopsy, please contact
Elizabeth Rafferty, MD
, Acting Director of Breast Imaging, at
617-726-3093.
We would like to thank Dr. Rafferty and
Michelle C. Specht, M.D., Surgical Oncology, for their advice and
assistance in the preparation of this article.
This article provided useful information about the appropriate use of imaging studies:
Note: clicking one of these options will close this window.
|
References
|
|
|
|
Fajardo,
L, Pisano, E, Caudry, D, Gatsonis, C, Berg, W, Connolly, J, Schnitt, S,
Page, D, McNeil, B and Radiologist Investigators of the Radiologic
Diagnostic Oncology Group V. (2004) Stereotactic and sonographic
large-core biopsy of nonpalpable breast lesions: results of the
Radiologic Diagnostic Oncology Group V study. Acad Radiol 11: 293-308
Liberman, L. (2002) Percutaneous image-guided core breast biopsy. Radiol Clin North Am 40: 483-500
Nurko, J and Edwards, MJ. (2005) Image-guided breast surgery. Am J Surg 190: 221-7
Perlet, C, Heywang-Kobrunner, SH, Heinig, A, Sittek, H, Casselman, J, Anderson, I and Taourel, P. (2006) Magnetic resonance-guided, vacuum-assisted breast biopsy: results from a European multicenter study of 538 lesions. Cancer 106: 982-90
Simon, JR, Kalbhen, CL, Cooper, RA and Flisak, ME. (2000) Accuracy and complication rates of US-guided vacuum-assisted core breast. Radiology 215: 694-7
Verkooijen, HM. (2002) Diagnostic
accuracy of stereotactic large-core needle biopsy for nonpalpable
breast disease: results of a multicenter prospective study with 95%
surgical confirmation. Int J Cancer 99: 853-9
|
|
|
|
|
|
|
|
