Left Lumpectomy with Wireless Seed Localization for Ductal Carcinoma In Situ

Breast-conserving surgery with radiation for early-stage breast cancers provides equivalent survival rates to mastectomy when all surgical margins are clear of residual cancer. For patients whose tumors are not palpable upon physical examination, preoperative localization of the malignant tissue to be removed is necessary. While wire localization is the traditional method of localization, a variety of wireless localization devices have become available as viable alternatives. Seed localizations provide several advantages over wire localization, including fewer scheduling issues, less patient anxiety, and reduced patient discomfort. Wire localization must occur on the day of the surgery, while seed localization may occur prior to surgery. Seed localization devices guide the breast surgeon to the target, typically a malignancy that must be removed in its entirety to give the patient the best likelihood of disease-free survival.

The patient is a 58-year-old postmenopausal woman who was seen for consultation regarding the management of newly-diagnosed ductal carcinoma in situ (DCIS) of the left breast detected on routine screening mammograms with no clinical or radiological evidence of lymph node involvement.

A routine screening mammogram identified a new 2.5-cm area of calcifications in the medial left breast. Radiologists did not identify any areas of concern in the right breast. Subsequent left breast core biopsy of the calcifications showed grade 2–3 estrogen-receptor-positive DCIS.

This patient underwent bilateral breast reduction surgery in 1992. A paternal cousin was diagnosed with breast cancer at age 55 and there is no other family history of breast or ovarian cancer. Because of the insignificant family history of breast and ovarian cancer, she was not recommended for genetic testing. She underwent a hysterectomy in 2013 due to fibroids and had no other surgical history.

This patient met with a breast oncology team 1 week after her biopsy-proven diagnosis of DCIS. On examination, the patient’s breasts appeared symmetric without palpable nodules or changes to the skin. She reported no nipple discharge. There was no axillary or supraclavicular adenopathy bilaterally.

She appeared to be healthy with no notable findings in her respiratory, cardiac, GI, musculoskeletal, or head and neck systems. No vitals were taken at her consultation with breast surgical oncology; however, at a recent prior office visit with her family medicine doctor, vital signs were as follows: BP 102/82, pulse 100, and BMI 37.44 kg/m.² Her Eastern Cooperative Oncology Group (ECOG) score was 0, suggesting she was capable of full unrestricted activity. A recent blood evaluation showed that levels of organ function parameters were acceptable for surgery. She has a history of hypertension, and no other notable medical conditions or surgical history that would exclude her from a breast-conserving procedure.

Screening mammogram demonstrated calcifications that led radiologists to call the patient back for a diagnostic mammogram. She previously received screening mammograms annually, going back to 2013, that the radiologists used for comparison. A bilateral diagnostic mammogram revealed indeterminate calcifications in the left central inner breast. The overall assessment from the diagnostic mammogram was BI-RADS 4 and stereotactic biopsy was recommended. The subsequent stereotactic biopsy was performed 2 weeks after screening mammogram, returning a diagnosis of DCIS.

Once a diagnosis was made, an MRI was performed to gain a more accurate picture of the shape and span of breast cancer. The MRI showed areas of fibroglandular tissue and mild background parenchymal enhancement. There was a signal void from the core biopsy clip at the site of the biopsy-proven DCIS in the left upper inner breast (approximately the 9:00 position, 5 cm from the nipple with the patient in prone position). There was non-mass enhancement at the biopsy site measuring at least 1.5 cm. Additional small foci of enhancement extended inferiorly from the biopsy site suggesting that overall enhancement could span up to 2.5 cm.

The enhancement of the skin of the medial breast was compatible with post-biopsy changes. There were additional scattered small foci of enhancement bilaterally. No axillary lymphadenopathy was seen.

A team of breast oncologists reviewed the radiological images and stereotactic biopsy results in conjunction with the patient’s medical history and physical exam. She had a palpable, grade 2–3, ER-positive DCIS of the left breast.

It is estimated that 1 in 8 women in the United States will develop breast cancer over the course of their lifetime, with an average five-year survival rate for women with invasive breast cancer at approximately 90%.^1, 2 Because of the likelihood of developing breast cancer, breast oncology societies recommend regular mammograms to track the progression of any abnormalities so that any malignancies can be caught at an early stage.³ With early detection, oncologists can begin local therapies as soon as possible.

Patients who undergo breast-conserving surgery have survival rates equal to those of patients who undergo total mastectomy, provided that the surgical team achieves clear margins.^4, 5 Although surgical equivalency has been demonstrated, patient anxiety related to the possibility of positive margins, indicative of residual cancer in the breast cavity, sometimes pushes patients towards mastectomy over lumpectomy. Surgeons typically recommend lumpectomy if the tissue to be removed is less than 25% of the patient’s breast size.

For this patient, the size of her cancer relative to her breast size indicated that we could provide favorable oncologic and cosmetic outcomes with breast-conserving surgery. Because of the lack of palpability of cancer on physical exam, tumor localization was indicated for this patient to effectively excise cancer and achieve clear surgical margins.

Currently, surgeons may choose between wire localization or wireless localization approaches such as magnetic seeds (MAGSEED), radiofrequency identification (RFID) tags (Faxitron), SAVI-SCOUT, radioactive seeds, and others.

Given the lack of palpability of any axillary, supraclavicular, or inframammary lymph nodes, absence of abnormal lymph nodes on radiological imaging, and the early stage of her breast cancer, it was decided that a sentinel lymph node biopsy was not in the best interest of the patient.

The patient preferred breast conservation to mastectomy to maintain her natural breast shape. It was explained to her that additional treatment recommendations would be based on the final pathology of tissue excised at the time of her lumpectomy and would be presented upon her return to the Breast Center postoperatively.

We planned a left lumpectomy under general anesthesia and informed consent was obtained.

This patient was brought to the operating room for excision of biopsy-confirmed DCIS in the medial left breast. After a discussion of the options, she opted to proceed with lumpectomy. Prior to surgery, the patient underwent bracketed magnetic seed localization of known cancer by a team of interventional radiologists.

In the operating room, the patient was placed in the supine position. Preoperative antibiotics were administered, and the left breast and axilla were prepped and draped in the standard surgical fashion. The procedure started by infiltrating 1% lidocaine with epinephrine and 0.25% bupivacaine without epinephrine in the breast for local pain control. A curvilinear incision was made using a #15 blade scalpel. Flaps were raised in all directions using Bovie electrocautery. We grasped the tissue surrounding the RFID tag using two Allis clamps. The lumpectomy specimen was then excised using a #15 blade scalpel. The specimen was sent to breast imaging for confirmation of the presence of the lesion within the specimen. We then excised margins in several directions to ensure clean margins. Each of the new margins was oriented such that a stitch was placed on the new margin. After removing the specimen, the wound was well irrigated and hemostasis was achieved using Bovie electrocautery. Hemoclips were left to assist in orienting postoperative radiation. The incision was closed using interrupted 3-0 Vicryl and running 4-0 Monocryl sutures. There was no unexpected bleeding during the excision of the mass. Steri-Strips and a sterile dressing were applied.

The patient was awakened from anesthesia and brought to the recovery room without incident. She was monitored by a team of perioperative nurses following surgery and was discharged the same day. She was instructed to resist lifting anything heavier than 10 lbs until she was seen again at her first postoperative visit. The patient reported no postoperative complications. Upon her return to the Breast Center 3 weeks after surgery, her incision was healing well and she was cleared to resume daily activities. We recommended adjuvant whole-breast radiation therapy (WBRT) in the prone position, beginning 4–6 weeks after surgery. After radiation, she would consider tamoxifen therapy to reduce the risk of a local recurrence or new primary breast cancer.

Numerous studies have demonstrated that breast-conserving surgery provides outcomes equivalent to those to mastectomy for the treatment of breast cancer if clean margins are achieved.^4, 5 For palpable breast cancers, surgeons may opt to perform a lumpectomy using touch as a guide for complete tumor resection. For breast cancers that are nonpalpable upon clinical exams, surgeons routinely opt for preoperative tumor localization procedures. Wired and wireless localizations for nonpalpable breast cancers are now considered standard of care to ensure that the targeted malignancy can be identified and excised during breast-conserving surgery.

Embedding wires transcutaneously has long been the standard of care for tumor localization; however, emerging wireless localization technologies offer many potential advantages over the standard wire technique. Seed localization procedures can occur prior to the day of surgery, eliminating the problems that may arise when trying to schedule wire localization and lumpectomy for the same day. Additionally, wireless devices offer a level of comfort that wires do not; wires protrude from the breast and are often taped down until the lumpectomy has begun. Initial studies have shown that the use of magnetic seed localization is safe in terms of the low migration rate from its intended target, and its ability to be detected in breasts of varying densities and depths below the skin.

Radioactive seeds can be placed prior to surgery and have shown similar surgical outcomes to those of wire-guided localization⁶; however, they require careful handling. Because of the regulations regarding radioactive materials, the radioactive seed must be handled and disposed of under the supervision of an authorized user.⁷ Alternatively, a recent study found equivalent rates of re-excision following both RFID tag-localized lumpectomies and wire-localized lumpectomies.⁸ One disadvantage of RFID tags is that they require a 14-gauge introducing needle that may lead to small incisions at the insertion site. Further studies are needed to examine the costs associated with the use of wires, magnetic seeds, and other wireless localization methods to definitively compare their respective merits.

Between 20–40% of women undergoing lumpectomy require a second operation to obtain clear surgical margins. DCIS, such as in this patient, may have erratic geometry that can be difficult to excise. Patients with these types of lesions may therefore benefit from the use of multiple localizing markers to bracket the edges of the tumor. It has been shown that use of multiple localizing wires to bracket larger or more erratically shaped tumors had similar rates of re-excision as patients with only one localizing wire.⁹ McGugin et al. demonstrated a higher re-excision rate in RFID tag-localized lumpectomies than in wire-localized lumpectomies when more than one tag/wire was used to bracket the target. Additional studies are warranted to determine whether multiple magnetic seeds or other wireless localization markers are as effective as wires for bracketing larger and erratically-shaped breast lesions.

• Lumpectomy kit
• RFID tag LOCalizer (Faxitron)
• BioVision (Faxitron)

Nothing to disclose.

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.