| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Technical Innovation |
Department of Radiology, University of North Carolina at Chapel Hill, CB 7510, Chapel Hill, NC 27599-7510.
Received April 21, 1999;
accepted after revision June 8, 1999.
Address correspondence to M.P. Braeuning.
Introduction
 Top Introduction Subjects and MethodsDiscussionReferences |
|---|
Serial physical examination, mammography, and sonography are important in assessing tumor response to chemotherapy. However, a problem that we have encountered is that in some patients response to chemotherapy is so good that no remaining physical or imaging evidence of the primary tumor remains. In these patients, the initial tumor bed must be localized by anatomic landmarks on the basis of prechemotherapy images. This may not be very precise and may impair the ability to assess for residual microscopic tumor. Patients with a good response to chemotherapy may also be candidates for breast conservation, so it is important that the exact tumor bed be excised. We have devised a method by which to mark the tumor bed with radiopaque markers before the institution of chemotherapy.
|
TopIntroductionSubjects and MethodsDiscussionReferences |
|---|
Initially, we used Hilal (MWCE-18-2.0-2-HILAL; Cook, Bloomington, IN) embolization microcoils. Since that time, Cook has developed another coil for this purpose (MCE-35P-1-2-VA; Cook), which is easier to introduce. The latter coils are made of platinum so that they do not interfere with breast MR imaging. Under imaging guidance and sterile conditions using lidocaine for anesthesia, the cephalad, caudad, medial, and lateral margins of the tumor are in turn localized and marked. The deep margin is not marked because the surgeons at our institution routinely remove tissue down to the pectoral fascia at the time of excision. The apex of the superficial margin is estimated by the surgeon at the time of excision. Localization under sonographic guidance is performed using a freehand technique similar to that used for a cyst aspiration. The apex or widest margin of the mass is identified and the coil deployed approximately 2 mm from the tumor edge. Under stereotactic guidance, the widest margin of the tumor should be targeted at the edge of the mass to determine the appropriate depth, but the coil should be placed approximately 2 mm away from and slightly past the visible edge of the tumor to ensure that its margins are encompassed. For sonographically guided deployment, an 18-gauge 7-cm-long vascular entry needle (SDN-18-7.0; Cook) is used. A longer 15-cm trocar version (DTN-18-15.0; Cook) can be used for stereotactic guidance.
The platinum coils deploy easily through an 18-gauge vascular entry needle. If the coil "catches" in the shaft of the vascular entry needle, it can be advanced into the breast using the needle stylet or a chasing bolus of sterile saline (Fig. 1A, Fig. 1B, Fig. 1C). The procedure has been well tolerated by patients.
|
|
|
After deployment of the coils, 90° lateral and craniocaudal mammograms are obtained as a baseline to document the exact location of the coils relative to the tumor. When the patient returns for follow-up mammograms after the second and fourth cycles of chemotherapy, the location of the coils can also be assessed, because as some of the tumors shrink the coils may draw closer together (Fig. 2). We have had no coils migrate after initial placement in the eight patients who have undergone this procedure to date. The complex shape of the coils likely deters migration.
|
At the time of definitive surgery, the four coils are marked with needle localization wires to resect the entire original tumor bed en bloc. The four localizing wires are placed from the shortest skin distance as in any standard localization. All wires can usually be placed from one projection. Unfortunately, the coils are not reproducibly visible on sonography; therefore, localizations are performed mammographically.
|
TopIntroductionSubjects and MethodsDiscussionReferences |
|---|
Clinical trials have shown that neoadjuvant chemotherapy is effective [4, 5, 6]. There are other theoretic advantages [6]. It enables direct assessment of the tumor's response to chemotherapy, which is an important prognostic indicator [7]. If the initial chemotherapeutic agent gives no response, the regimen can be changed. Also, the tumor may be down-staged so that less aggressive surgery may be feasible.
With neoadjuvant chemotherapy, the exact effect on tumor shrinkage is unpredictable. It has been shown that mammographic and physical examination findings after chemotherapy do not necessarily correlate with histologic findings [8]. Until this correlation can be predicted, the original tumor bed must be resected to ensure removal of microscopic disease. In addition to ensuring removal of the original tumor bed, the approach we describe will allow correlation of the mammographic appearance with the histologic appearance and may provide useful information in determining how large solid tumors are destroyed by chemotherapy. Edeiken-Moore et al. [9] described a similar method of marking tumor beds with metallic markers using a 15-gauge needle. The method outlined in our report may help obtain this information with the added benefit of using an 18-gauge needle for placement.
In summary, marking the tumor bed before the institution of chemotherapy can now be relatively easily accomplished and may offer some additional insight into tumor biology.
|
TopIntroductionSubjects and MethodsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  R Warren and P Kessar A method of coil localization for breast lesions seen only on MRI Br. J. Radiol., June 1, 2001; 74(882): 548 - 551. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Phillips, H. Gabriel, C. E. Comstock, and L. A. Venta Sonographically Guided Metallic Clip Placement After Core Needle Biopsy of the Breast Am. J. Roentgenol., November 1, 2000; 175(5): 1353 - 1355. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
