| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Breast Imaging |
1 From the Departments of Radiology (S.H., M.W., H.C.) and Obstetrics and Gynecology (M.M.), Lainz Hospital, Wolkersbergenstrasse 1, 1130 Vienna, Austria. Received November 26, 2001; revision requested February 11, 2002; final revision received August 8; accepted August 21. Address correspondence to S.H. (e-mail: s.pankl@telering.at).
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
MATERIALS AND METHODS: For 91 benign lesions that had been sampled at either stereotactic or US-guided directional vacuum-assisted breast biopsy performed with 11-gauge needles, clinical, mammographic, and US changes were evaluated 1 week after biopsy; 6-month follow-up findings were available for 74 lesions. The subjective outcome of the procedure and patient satisfaction were assessed on the basis of a patient-completed questionnaire that incorporated a multistage scoring system. Statistical analysis of scores for condition for both biopsy methods was performed with the 
2 test.
RESULTS: Adverse events occurred during the procedure in four patients. Clinically visible hematomas were observed at 1-week follow-up in 79% of patients. Densities were observed on mammograms in 46% of patients 1 week after biopsy; hematomas with a maximum diameter of 2 cm were seen on sonograms in 74%. Six months after biopsy, mammography revealed discrete architectural changes in one case. No abnormalities were found at 6-month follow-up US. Fifteen patients had various complaints during the procedure; six reported feeling constrained during the first few days after biopsy, and one patient was not satisfied with the cosmetic result. No patient reported a retrospective preference for surgical biopsy instead of directional vacuum-assisted biopsy. Analysis of scores for the stereotactic and US-guided methods revealed a significant difference (P < .001) in favor of the stereotactic method for condition during biopsy, while scores for condition in the first days after biopsy were more equally distributed between the two methods (P = .386).
CONCLUSION: Directional vacuum-assisted 11-gauge needle biopsy of the breast is well accepted by patients and rarely produces changes that may alter the mammographic or sonographic appearance of the breast at 6-month follow-up.
© RSNA, 2003
Index terms: Biopsies, complications, 00.1261 • Biopsies, technology, 00.1261 • Breast, biopsy, 00.1261
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
Thus, the question remains as to whether the removal of larger volumes of breast tissue, obtained contiguously from a single site in the breast at directional vacuum-assisted 11-gauge needle biopsy, results in ambiguous mammographic or sonographic findings at follow-up examinations. Furthermore, to the best of our knowledge, patient acceptance of the procedure has not been described in the literature to date.
The purpose of our study was to evaluate short- and long-term changes seen on mammograms and US images after stereotactic or US-guided directional vacuum-assisted 11-gauge biopsy of breast lesions.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
Methods of performing a breast biopsy with a directional vacuum-assisted instrument (Mammotome, Biopsys Medical, Irvine, Calif; or Mammotest, Fischer Imaging, Denver, Colo) have been previously described (9–11). Although these devices are called directional vacuum-assisted instruments, no multidirectional component is used in the biopsy procedure; the procedure is performed by means of shaving from the bottom of the lesion.
Forty-three lesions were recommended for biopsy because of a density or mass detected at mammography or US and 65 because of the presence on mammograms of indeterminate microcalcifications without concomitant mass formation. In accordance with observations in previous reports (12), in our study biopsy was sometimes performed due to a patient’s wish to undergo histologic evaluation of the lesion rather than mammographic surveillance, even if there was no mammographic or US indication of malignancy. In all patients, 3–6 mL of buffered 1% lidocaine was administered intradermally for local anesthesia, and 8–12 mL of 1% buffered lidocaine with epinephrine (premixed in a ratio of 100,000 mg lidocaine to 1 mg epinephrine) was administered for deeper anesthesia. After the procedure, local pressure and ice bags were routinely applied to the breast for a duration of approximately 10 minutes. In no case was a repeat diagnostic biospy required.
Histologic findings from the 11-gauge needle biopsies were benign in 91 (84%) cases (41 fibroadenomas, 50 cases of fibrocystic disease), whereas ductal carcinoma in situ was detected in five (5%) cases; invasive ductal breast cancer, in 11 (10%) cases; and lobular invasive carcinoma, in one (1%) case.
Because patients with diagnosed malignancies underwent surgery within 2 weeks after biopsy, only 91 patients with benign findings were included in the study.
Evaluation and Imaging
At the time of biopsy and in subsequent letters, patients were asked to undergo clinical examination, mammography, and US of the breast 1 week and 6 months after the procedure. Six-month follow-up investigations were performed in 73 patients (74 of 91 benign lesions). Results of clinical, mammographic, and US examinations 1 week and 6 months after biopsy were compared with those of the most recent mammographic and US examinations performed before biopsy and those of the preliminary mammographic examination at the time of biopsy. Results were evaluated by two authors (S.H., M.W.) in consensus.
Mammograms were obtained in craniocaudal and mediolateral oblique views with dedicated mammography units (Senographe 600 T; GE Medical Systems, Milwaukee, Wis). US was performed with a 10-MHz linear-array transducer and an Esaote AU4 unit (Esaote Biomedica, Genoa, Italy) with standardized system settings optimized for breast imaging.
Patient and lesion information recorded included the following parameters: age of the patient on the day of biopsy, mean lesion diameter in millimeters ([maximum length + maximum width]/2), general type of the lesion (mass or microcalcification), and whether lesion removal was complete (ie, there was no more mammographic or US evidence of the lesion) or partial.
Data from the biopsies were recorded according to procedural variables such as adverse events and/or complications, pain management, tissue harvesting time, number of specimens per lesion submitted to the pathology department, and required dose of local anesthesia and, when applicable, vasopressin.
Image Interpretation
Each radiologist was instructed to interpret the first follow-up mammograms and sonograms just as those obtained after open surgical biopsy are interpreted at our institution. Interpretation included an assessment of the biopsy site for lesion growth, presence of residual lesion, and any signs of distortion or scarring that might have been caused by the biopsy procedure.
At each follow-up examination, clinical, mammographic, and US changes of the breast biopsy site or target lesion were recorded and tabulated according to descriptive parameters. Evaluation of mammograms and sonograms was performed by two authors in consensus.
Mammographic features identified for analysis included local skin changes (thickening, flattening, retraction), focal architectural distortion with no central density or mass at the biopsy site, increased focal density at the biopsy site (seen on two orthogonal projections) without distinct margins and interspersed with fat, formation of a mass (ie, a fluid collection or soft-tissue mass), calcification, lipid cyst formation as evidence of fat necrosis, foreign bodies, and suture granulomas.
Parameters assessed on sonograms included the presence of fluid collection or focal architectural distortion and the formation of masses or calcification at the biopsy site. The progression, stability, or resolution of clinical, mammographic, and US findings over time were analyzed by two authors (S.H., M.W.) in consensus.
Patient Questionnaire
After the biopsy, patients were asked to complete a questionnaire (Fig 1) that was usually returned at the first follow-up investigation 1 week later. According to a subjective multistage scoring system in which 1 represented excellent; 2, good; 3, varying; 4, satisfactory; and 5, not satisfactory, each patient classified her acceptance of the procedure with regard to her condition and specific complaints during the biopsy (pain, positioning, anxiety) and during the first few days after the procedure (pain, need for pain relief, physical constraints in daily life), the cosmetic result of the procedure, and her retrospective opinion regarding the alternative of surgical biopsy. Evaluation of completed patient questionnaires was performed by one author (S.H.).
|
2 test. P < .05 was considered to indicate a statistically significant difference. |
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
|
During stereotactic biopsy, severe bleeding occurred in two (2%) patients; a vasovagal reaction occurred in another two (2%) patients. In no case, however, did the biopsy have to be terminated before a number of specimens sufficient for histopathologic diagnosis were obtained.
The most common feature at the clinical examination performed 1 week after the biopsy was a superficial hematoma of various degrees (in 72 [79%] patients). A slight local inflammatory reaction was observed in one (1%) patient (Table 2). No clinical changes were recorded at the 6-month follow-up examination.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Agreement for the two readers 1 week after the biopsy procedure, as well as at the 6-month follow-up, was 100%.
Completed questionnaires concerning the patient’s subjective satisfaction were available for 88 patients (Tables 5–7). Regarding their condition during the biopsy, a score of 1 (excellent) was assigned by 69 (90%) of the patients who underwent stereotactic biopsy and by four (36%) of the patients who underwent US-guided biopsy. A score of 2 (good) was assigned by six (8%) patients after stereotactic biopsy and by five (46%) after US-guided biopsy. A score of 3 (varying) was assigned by two (3%) patients after stereotactic biopsy and by two (18%) after US-guided biopsy.
|
|
|
With regard to their condition during the first few days after biopsy, 81 patients (72 [94%] of the patients who had undergone stereotactic biopsy and nine [82%] of the patients who had undergone US-guided biopsy) assigned a score of 1 (excellent), four patients (three [4%] of the patients who had undergone stereotactic biopsy and one [9%] of the patients who had undergone US-guided biopsy) assigned a score of 2, and three patients (two [3%] of the patients who had undergone steretotactic biopsy and one [9%] of the patients who had undergone US-guided biopsy) assigned a score of 3.
Of four patients who assigned a score of 2, two reported that they needed medication (pain relief, antibiotics) during the first few days after the biopsy, while another two reported that they felt constrained in daily life. Two of the three patients who assigned a score of 3 also reported feeling constrained in daily life, and one was not satisfied with the cosmetic result at the incision site.
No patient reported a retrospective preference for open surgical biopsy instead of the directional vacuum-assisted biopsy technique.
Statistical analysis of scores for the stereotactic and US-guided biopsy methods revealed a significant difference (P < .001) in favor of the stereotactic method in terms of condition during biopsy, while scores for condition in the first days after biopsy were more equally distributed between the two methods (P = .386).
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
Stereotactic or US-guided breast biopsy with large-core needles has gained acceptance as an alternative to automated needle-guided biopsy for histopathologic diagnosis and also for the removal, within certain limits, of breast lesions (9–11).
According to the investigators of a number of studies (6,9,11,16,17), four factors may primarily account for the better performance of directional vacuum-assisted devices: (a) ease of obtaining a larger number of specimens, (b) higher average specimen weights, (c) higher percentage of breast tissue (versus blood clot) per specimen, and (d) ability to perform contiguous breast tissue acquisitions.
The specimen weights in a turkey breast tissue model reported by Berg et al (18) were similar to the weights of specimens obtained from human tissue by Burbank and Forcier (16,17) during actual clinical breast biopsy. However, Berg et al (18) observed significantly greater specimen fragmentation with directional vacuum-assisted biopsy systems than with core biopsy systems.
Biopsy of the breast at which approximately five specimens per lesion are acquired with an automated needle device does not produce changes or deformities that can be recognized on subsequent mammograms (19,20). The question remains as to whether removal of larger volumes of breast tissue that are obtained contiguously from a single site in the breast results in the presence of confusing mammographic lesions at postbiopsy follow-up.
In our study, the first clinical follow-up investigation, mammography, and US were performed 1 week after directional vacuum-assisted large-core biopsy so that we could evaluate short-term results and assess the patients’ opinions regarding the biopsy procedure at a time when it was still fresh in their minds. Long-term follow-up was scheduled for 6 months after biopsy, because the greatest amount of mammographic changes are usually observed between the immediate postoperative period and 6 months after surgical biopsy (1). Sickles and Herzog (1) described a gradual resolution of findings, especially in patients evaluated during the first 6 months after biopsy compared with those evaluated at a later time. In the study of Brenner and Pfaff (13), regression analysis revealed a stable trend, with no substantial progression or resolution of findings, in patients initially evaluated 1 year after biopsy. Therefore, the authors inferred that a patient’s condition tends to become stable between 6 months and 1 year (13). Thus, in the event of alterations seen 1 year after biopsy or later, the radiologist may confidently recommend intervention (13).
Because a large number of patients in our study were referred for biopsy owing to the presence of indeterminate microcalcifications, 80 lesions were selected for stereotactic directional vacuum-assisted 11-gauge needle biopsy, whereas 11 lesions were selected for US-guided directional vacuum-assisted 11-gauge needle biopsy because they were exclusively or better visualized at US. At follow-up assessment, however, each patient was examined with mammography and US because, depending on the composition of breast tissue, discrete changes such as small fluid collections are better appreciated at US.
The most common findings 1 week after biopsy were a well-defined radiodense mass at mammography and a collection of fluid at US. The collection of fluid was larger than 1 cm in only four cases. Hematomas appeared as round masses of variable density with somewhat poorly defined margins. Hematomas typically resolve within 2–4 weeks, although some persist for 8 weeks or longer (15). As the hematoma resolves, residual distortion may occur. Some hematomas evolve into oil cysts or areas of fat necrosis. In our series, only one hematoma resulted in a discrete change at mammography; on mammograms obtained 6 months after biopsy, this hematoma appeared as an area of increased focal density that was without distinct margins and was interspersed with fat. Because the location of this finding corresponded with that of the biopsy site and this finding was not indicative of malignancy on either mammograms or sonograms, further follow-up examinations at routine intervals were recommended. No other changes were observed 6 months after biopsy on mammograms or sonograms.
The results of this study suggest that directional vacuum-assisted large-core needle biopsy of the breast rarely produces changes that alter the mammographic or sonographic appearance of the breast at 6-month follow-up. The absence of mammographic evidence of scarring, architectural distortion, and fat necrosis suggests that 11-gauge needle biopsy of the breast is not a particularly traumatic procedure. Our findings are in agreement with those of Kaye et al (5), Burbank (6), Jackman et al (7), and Lamm and Jackman (8), who observed that stereotactic breast biopsies performed with a directional vacuum-assisted large-core probe did not produce deformities or result in confusing mammographic findings at short- and long-term follow-up imaging. Although these researchers did not review mammograms obtained in patients who underwent US-guided large-core needle biopsy, one would expect evaluation of the results of that procedure to yield similar findings, because the needle and biopsy gun used for US-guided procedures are similar or identical to the needles and biopsy guns used for stereotactic procedures.
According to the investigators of a number of studies (6,9,11,16,17), it appears that at least 875 mg of breast tissue (25 specimens times 35 mg per specimen) can be removed with a directional vacuum-assisted instrument without the risk of producing a confusing mammographic finding at follow-up imaging.
Specific postsurgical changes (1–4,12,15) that could make it difficult to distinguish between scarring or architectural distortion and malignant disease (21) have not been seen on mammograms obtained after needle biopsies. This, in addition to other considerations such as economic value and cosmetic results, is a further argument in favor of needle biopsy versus surgical biopsy.
Insertion of the 11-gauge biopsy device or the Mammotome requires an incision that is approximately 3–5 mm wide. The incisions typically heal in 1–2 weeks and could not be accurately identified at 6-month follow-up in this study. Hematomas of various degrees occurred during the first few days after biopsy in most lesions; one patient had a slight local inflammatory reaction. No clinical changes were recorded at the 6-month follow-up investigation.
Seventy-three (83%) of the patients in our series reported that they felt excellent during the biopsy, four (5%) reported that they felt uneasy owing to uncomfortable positioning, three (3%) reported that they experienced pain despite the provision of additional local anesthesia, and eight (9%) reported that they felt constrained by intense anxiety during the procedure.
According to the presented data, patients who underwent US-guided directional vacuum-assisted biopsy felt more uncomfortable during the procedure than those who underwent stereotactic biopsy. This may have been due to differences in the biopsy techniques, such as the use of a handheld US device for guidance in the former procedure. In the stereotactic technique, compression of the breast might relieve pain and simplify the biopsy procedure by reducing patient and breast movement as well as bleeding. In addition, the patient’s direct contact with the invasiveness of the procedure in the US-guided technique may play a role. (Patients undergoing stereotactic biopsy are not directly confronted with the invasiveness of the procedure because the patient lies on the table and the biopsy is performed beneath the table, where it is invisible to the patient.)
At 1-week follow-up, however, scores were approximately equally distributed between the two techniques with regard to well-being and complications, and no patient reported a retrospective preference for open surgical biopsy instead of either method of directional vacuum-assisted biopsy.
Several limitations of this study should be taken into consideration: Because surgical tumor excision was scheduled as soon as possible after biopsy in patients with diagnosed malignancies, as well as for psychological reasons, only patients with benign findings were included in the study. Women may view the biopsy procedure more favorably if the histologic results are benign. Also, the appearance of malignancies that have been sampled at large-core biopsy may be different from the appearance of the benign lesions evaluated in this study.
Material sufficient for histopathologic evaluation was obtained in all cases without the need for a repeat biopsy. A repeat biopsy or even subsequent open surgery, which might become necessary for several reasons (eg, insufficient material, wrong positioning, patient movement, adverse events, technical problems at biopsy, or contradictory histopathologic and imaging results), may certainly cause patients to be dissatisfied and to lose confidence in the technique.
Also, in an event that is somewhat contradictory to those reported in the literature (22), of the 91 benign lesions in our study, none showed evidence of atypical ductal hyperplasia, radial scar, or other findings at histologic evaluation of the biopsy specimens that would be inconclusive for the diagnosis of ductal carcinoma in situ or invasive carcinoma and would have required recommendation of subsequent excisional biopsy. This event may be important, because the need to undergo surgical biopsy after a needle biopsy has revealed benign histologic findings may cause some patients to perceive the biopsy procedure as a negative experience.
The presented results suggest that stereotactic or US-guided directional vacuum-assisted 11-gauge needle biopsy of the breast is a largely uncomplicated procedure that is well accepted by patients and does not produce parenchymal scarring, architectural distortion, fat necrosis, or other identifiable changes such as those encountered after surgical biopsy; thus, use of this biopsy method does not pose a diagnostic dilemma in the subsequent interpretation of routine screening mammograms and sonograms.
|
FOOTNOTES |
|---|
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| RADIOLOGY | RADIOGRAPHICS | RSNA JOURNALS ONLINE |
