Lumpectomy with Sentinel Lymph Node Biopsy

Breast-conserving therapy (BCT). Two operations combined: partial (segmental) mastectomy of the tumor with negative margins plus sentinel lymph node biopsy for axillary staging. For contraindications to BCT or SLNB-positive salvage, see total mastectomy and ALND. For staging biology and adjuvant decisions, see the breast topic review.

Procedure Snapshot

• Indication: Early-stage invasive breast cancer (T1–T2) or DCIS candidate for BCT. Requires ability to obtain negative margins with acceptable cosmesis and availability of postoperative whole-breast radiation.
• Contraindications to BCT:
  • Absolute — inability to receive radiation (pregnancy in a trimester that would require radiation during pregnancy; prior therapeutic chest / breast radiation), diffuse suspicious microcalcifications, multicentric disease, persistent positive margins after reasonable re-excision, inflammatory breast cancer.
  • Relative — active connective-tissue disease (scleroderma, lupus), tumor > 5 cm without good cosmetic option, large tumor-to-breast ratio (consider neoadjuvant to downstage).
• Margin standard: “No ink on tumor” for invasive cancer (SSO/ASTRO consensus). 2 mm margin for pure DCIS.
• Expected duration: 60–120 min combined.
• Positioning: Supine, ipsilateral arm abducted 90° on a padded board. Ipsilateral hemithorax and axilla prepped into the field. Draw the incision on the awake patient in preop if feasible (Langer’s lines / cosmetic outcomes).
• Special instruments: Electrocautery, Bovie extender, right-angle retractors (Army-Navy, Green, Ragnell), fine tissue forceps, marking clips (Ligaclips) for cavity margins, specimen radiograph capability, localization system (see below), gamma probe and/or blue dye and/or magnetic probe for SLNB.
• Prep: Cefazolin within 60 min. Confirm side / site with the awake patient. Verify localization marker location on the day-of imaging.
• Frozen section: Not routine for margins on breast; frozen SLN is reasonable for select cases (attending preference; SSO guidelines allow).

Localization Methods

Non-palpable cancers require preoperative localization so the surgeon can find the lesion in the OR. The gold-standard workflow used to be the wire; now most breast programs use one of several wire-free systems that can be placed days to weeks before surgery.

Wire (needle) localization — traditional

• Radiologist places a hooked wire under mammographic or ultrasound guidance the morning of surgery.
• Surgeon follows the wire down to the lesion; excises with a rim of normal tissue around the tip.
• Downsides: patient discomfort with a wire projecting from the breast, same-day radiology scheduling bottleneck, wire migration, wire transection with cautery, no MRI localization option.

Radioactive seed localization (RSL) — historical / niche

• I-125 (or Pd-103) titanium-encapsulated seed placed 1–5 days pre-op.
• Detected intra-operatively with a gamma probe — same probe used for Tc-99m sentinel node.
• Advantages: decoupled from OR day.
• Downsides: radiation-safety logistics (chain of custody, disposal), regulatory burden — most centers migrated to non-radioactive systems.

Savi Scout (radar / infrared) — Baylor Dallas + JPS Fort Worth

• Passive radar reflector (< 12 × 1.6 mm) placed percutaneously by radiology up to 30 days pre-op (FDA-approved indefinitely for lesion localization; commonly limited by imaging follow-up needs).
• Console emits an infrared trigger + radar pulse → reflector returns a distinct signal → handheld probe gives audible tone + distance in mm.
• No radiation. No magnet. MRI-safe up to 3 T (small susceptibility artifact).
• Metallic surgical instruments do not interfere — regular cautery, standard forceps all fine.
• Depth limitation — reflector must sit within ~6 cm of the skin surface for reliable signal.

LOCalizer (RFID) — Baylor Waxahachie

• Passive RFID tag (~ 11 × 2 mm) with a unique ID number, placed by radiology under image guidance days to weeks pre-op.
• Detected with a proprietary handheld probe → distance in mm + tag ID displayed on the console. Multiple tags can be uniquely identified in the same breast, useful for multifocal disease.
• No radiation, no magnet, no ferromagnetic instrument concerns — regular cautery, standard forceps all fine.
• MRI compatible with minimal artifact, so surveillance imaging is not compromised.
• Depth reach ~ 6 cm from the probe surface.

Magseed (magnetic)

• Small 5 mm magnetic seed (surgical-grade steel, magnetized) placed by radiology under image guidance up to years pre-op.
• Detected with the Sentimag handheld probe → distance in mm, audible tone.
• No radiation. MRI compatible up to 3 T but creates a small susceptibility artifact (~4 cm) that can obscure surveillance imaging for a period.
• Ferromagnetic surgical instruments interfere with the signal. Many operators use titanium or plastic retractors and forceps during the localization step, then switch back to standard instruments once the lesion is grossly identified. Standard monopolar cautery is generally OK but the signal quality degrades near steel.

Molli, Sirius Pintuition, and other magnetic markers

• Magnetic-based systems similar to Magseed with slightly different probes and marker geometries.
• Same instrument caveat: ferromagnetic tools interfere.

SLNB Tracers

The sentinel node hypothesis: lymphatic drainage from the tumor bed follows a stepwise path, and the first (“sentinel”) node accurately reflects the biology of the rest of the basin. Modern SLNB uses one to three tracers, often combined for redundancy.

Tc-99m sulfur colloid (radiotracer)

• Peritumoral, subareolar, or subdermal injection 2–24 hr preop in nuclear medicine.
• Handheld gamma probe identifies the “hot” node.
• Standard of care for most cases. Detection rate ~95%.
• Contraindications: pregnancy (relative — reduced-dose protocol available), previous axillary surgery on the same side (drainage unpredictable), palpably positive axilla (skip SLNB, go to ALND).

Isosulfan blue (Lymphazurin 1%)

• Peri-areolar injection at the start of the case, 5–15 min prior to axillary incision.
• Turns the sentinel node visibly blue.
• Contraindication: anaphylaxis — reported rate ~1 in 100 (higher than methylene blue). Any prior reaction is an absolute contraindication.
• Pregnancy category C — avoid.

Methylene blue

• Alternative dye when Lymphazurin unavailable or contraindicated.
• Do not inject dermally at high concentration — causes skin necrosis (“blue tattoo” complication).
• Caution in G6PD deficiency (hemolysis) and pregnancy (avoid).
• Cheaper, easier to obtain, similar detection rates in most series.

Indocyanine green (ICG) — near-infrared fluorescence

• Injected peri-areolar; visualized through skin and axilla with a NIR camera (Firefly on the robot, Stryker SPY, or dedicated open-camera systems).
• No radiation. No blue tattoo. No anaphylaxis risk.
• Increasingly used as a stand-alone tracer or in combination with Tc-99m for redundancy.

Magtrace (superparamagnetic iron oxide / SPIO / Sienna+) — the “plastic instruments” tracer

• Injected day-of-surgery or up to 30 days pre-op — decoupled from OR-day nuclear medicine scheduling.
• Detected with the same Sentimag probe used for Magseed.
• Ferromagnetic surgical instruments interfere with the magnetic signal, exactly like Magseed. Retractors, forceps, and needle drivers used during the sentinel-node search need to be non-ferromagnetic (titanium or plastic).
• Creates a brown discoloration of the tissue at the injection site — cosmetically resolves over months but can be off-putting.
• Detection rates comparable to Tc-99m + blue dye.

Practical combinations

• Tc-99m + blue dye — classic double tracer, ~99% detection when combined.
• Tc-99m + ICG — increasingly popular; NIR gives real-time visual, gamma probe confirms.
• Magtrace alone — where nuclear medicine access is limited (community, freestanding centers).

Step Workflow — Lumpectomy + SLNB (Combined)

1. Preop confirmation
   • Confirm side, site, imaging (mammogram/US/MRI reports on screen), localization marker on the day-of image.
   • Draw skin incision on the awake patient — position over the tumor at Langer’s lines or in a curvilinear pattern parallel to the areolar contour.
   • Inject dye tracers (blue dye peri-areolar) in the OR at the start of the case.
2. Access and lesion localization
   • Skin incision as marked.
   • Use the localization system probe (Savi Scout / Magseed / LOCalizer / wire) to navigate to the lesion. For Magseed / Magtrace, ensure non-ferromagnetic instruments during the localization step.
   • For a palpable tumor without localization marker, use palpation and tactile guidance; ultrasound guidance is a reasonable adjunct.
3. Partial mastectomy (lesion excision)
   • Excise the lesion with a 1 cm gross margin of surrounding normal tissue as a single specimen.
   • Orient the specimen with sutures: short → superior, long → lateral (or the standard your institution uses). A three-suture technique also works (short, long, deep) — critical for margin re-excision planning.
   • Send specimen radiograph for lesions with clips or calcifications to confirm target excision.
   • Place radiopaque clips on the walls of the cavity (superior, inferior, medial, lateral, deep) — guides post-op radiation boost.
4. Cavity assessment
   • Achieve hemostasis in the cavity. Do not obliterate the cavity with sutures unless doing oncoplastic closure — modern radiation oncology prefers a defined cavity for the boost.
   • Consider cavity shave margins (“SHAVE” trial technique) — additional circumferential shave decreases positive-margin re-excision by ~50%.
5. Separate SLNB incision
   • Small (~3 cm) transverse incision in the axilla, just below the axillary hairline.
   • Divide skin, subcutaneous fat, and the clavipectoral fascia.
   • Use the gamma probe to identify the “hottest” node; visually identify blue and/or fluorescent nodes.
   • Remove all hot (> 10% of hottest node ex vivo), blue, and palpably suspicious nodes. Rule of thumb: remove all nodes with counts > 10% of the hottest ex-vivo node.
   • Send for pathology (frozen section or permanent depending on institutional protocol).
6. Closure
   • SLNB incision: closed in layers — deep dermal 3-0 Vicryl, subcuticular 4-0 Monocryl.
   • Lumpectomy skin closure: deep dermal 3-0 Vicryl, subcuticular 4-0 Monocryl, Steri-Strips + Dermabond.
   • Rarely drains for lumpectomy alone.
   • No pressure dressing over the SLNB site — encourages seroma. Light dressing.

Rapid-Fire Questions

• Q: What margin is required for invasive cancer? A: “No ink on tumor” (SSO/ASTRO 2014).

• Q: What margin is required for pure DCIS? A: 2 mm.

• Q: Contraindications to BCT? A: Absolute — pregnancy requiring radiation during pregnancy, prior chest/breast radiation, multicentric disease, persistent positive margins, inflammatory breast cancer. Relative — active connective-tissue disease, tumor > 5 cm without good cosmetic option, large tumor-to-breast ratio.

• Q: Difference between multifocal and multicentric? A: Multifocal = multiple tumors in the same quadrant (BCT OK). Multicentric = multiple tumors in different quadrants (BCT contraindicated).

• Q: ACOSOG Z0011 — what did it show, and who does it apply to? A: T1–T2 invasive cancer, clinically node-negative, receiving BCT + whole-breast RT, with 1–2 positive SLNs — no benefit to completion ALND. No difference in local recurrence, disease-free, or overall survival. Applies specifically to that population; does not apply to mastectomy patients (though AMAROS extends similar logic).

• Q: SLNB with 3+ positive nodes on frozen — next step? A: ALND — outside Z0011 criteria.

• Q: SLNB after neoadjuvant chemotherapy — issues? A: Higher false-negative rate. Improved with (a) dual tracer (Tc-99m + blue), (b) removing ≥ 3 nodes, (c) clip-and-remove for the previously biopsy-proven positive node (targeted axillary dissection, TAD).

• Q: SLNB in a patient with prior axillary surgery — issues? A: Disrupted lymphatics → unreliable drainage → high false-negative rate. Reasonable in select recurrent cases with lymphoscintigraphy proof of drainage.

• Q: SLNB in pregnancy — safe? A: Tc-99m — yes with reduced-dose protocol (fetal exposure < 5 mGy). Blue dye — no (allergy risk, category C). Avoid ICG data limited.

• Q: Bloody nipple discharge — most common cause? A: Intraductal papilloma (not premalignant). Diagnose by duct excision; treat by subareolar resection of the involved duct + papilloma.

• Q: Isolated tumor cells (< 0.2 mm) in the SLN — does this constitute nodal metastasis? A: No — pN0(i+). Does not stage as N1. No indication for ALND on this alone.

• Q: How many nodes should you take at SLNB? A: All hot (> 10% of hottest ex-vivo), all blue, all clinically suspicious — usually 1–4 nodes. Not a fixed number.

• Q: Localization marker inside the tumor but tumor is inside the seed’s zone-of-artifact on MRI — problem? A: Yes for Magseed / Magtrace — magnetic markers create susceptibility artifact that can obscure imaging for up to 6 months. Not an issue for Savi Scout radar reflectors or LOCalizer RFID tags.

• Q: Patient with prior anaphylaxis to a lymphangiogram dye — which tracers to avoid? A: Isosulfan blue — absolutely avoid. Use Tc-99m alone, methylene blue (different structure, minimal cross-reactivity), or ICG / Magtrace.

• Q: Which localization technology is best for a patient who will get a post-op MRI? A: Savi Scout radar reflector or LOCalizer RFID — minimal MRI artifact. Magseed / Magtrace create meaningful susceptibility artifact.

• Q: Tumor near the pectoral fascia — what do you do? A: Take the pectoral fascia with the specimen. It’s a natural anatomic margin and does not add morbidity.

Critical Anatomy

• Breast blood supply: internal thoracic (mammary) — dominant, ~60%; lateral thoracic; thoracoacromial; posterior intercostals.
• Breast venous drainage: parallels arteries → axillary and internal mammary systems → superior vena cava. Batson’s venous plexus — valveless system, direct hematogenous route to the vertebral bodies (spinal metastases).
• Lymphatic drainage:
  • ~ 97% → axillary (level I → II → III).
  • ~ 3% → internal mammary chain (deep to the pectoral fascia along the ITA).
• Cooper’s ligaments — fibrous suspensory ligaments; tethering leads to skin retraction (a cancer sign).
• Axilla — level system:
  • Level I — lateral to pectoralis minor.
  • Level II — posterior to pectoralis minor.
  • Level III — medial to pectoralis minor. Standard breast ALND takes I + II.
• Rotter’s nodes — interpectoral nodes between pec major and pec minor. Usually not sampled.
• Nerves of the axilla:
  • Long thoracic (C5–7) → serratus anterior. Injury = winged scapula.
  • Thoracodorsal (C6–8) → latissimus dorsi. Injury = weakness in adduction / internal rotation of the arm (“push out of a chair” test).
  • Medial pectoral → pec major and pec minor. Lateral pectoral → pec major only.
  • Intercostobrachial (T2) → sensory to the medial upper arm. Frequently sacrificed in ALND; injury causes upper-arm dysesthesia but is not a functional deficit.
• Danger zones:
  • Long thoracic on the medial chest wall along serratus.
  • Axillary vein (most cephalad structure) — do not dissect above it.
  • Chest wall pleura on deep dissections — pneumothorax risk.

Informed Consent Highlights

• Risks:
  • Positive margin re-excision ~ 15–20% (lower with cavity shave margins).
  • Hematoma / seroma — common; usually self-limited.
  • Infection ~ 2–5%.
  • Cosmetic asymmetry — depends on lumpectomy volume relative to breast size.
  • Lymphedema after SLNB — ~ 5–7% (vs 20–30% after ALND). Institutions running a SOZO bioimpedance surveillance program (baseline preop L-Dex score, then serial post-op measurements) catch subclinical lymphedema before it becomes clinically apparent; the PREVENT trial (Ridner 2019) showed that early compression triggered by a rising L-Dex reduced progression to chronic lymphedema from ~35% to ~7%.
  • Chronic pain / paresthesias in the axilla — up to 20% mild, ~5% clinically significant.
  • Nerve injury — long thoracic (winged scapula), thoracodorsal, intercostobrachial (medial arm numbness — very common, ~ 60%).
  • Blue tattoo / brown discoloration — with isosulfan blue or Magtrace injection.
  • Anaphylaxis with isosulfan blue ~ 1%.
  • Skin necrosis with dermal methylene blue.
  • False-negative SLNB ~ 5–10%.
  • Standard: bleeding, DVT, cardiopulmonary, death (very rare).
• Benefits: Breast preservation, oncologic outcomes equivalent to mastectomy for appropriate candidates (NSABP B-06, Milan), single-day recovery.
• Alternatives:
  • Total mastectomy ± SLNB — for patients who prefer or who fail BCT criteria.
  • Neoadjuvant chemotherapy — to downstage and enable BCT for larger tumors.
  • Endocrine therapy alone in older ER-positive patients with T1 disease (NCCN allows omission of surgery in select > 70 y).

Post-op Considerations

• Disposition: Same-day discharge.
• Diet / activity: Regular diet; light activity POD 0–1; avoid heavy lifting > 10 lb for 2 weeks. Shoulder ROM day 1 to prevent frozen shoulder.
• Analgesia: Acetaminophen + NSAID; short opioid course only if needed.
• Dressing / bra: Supportive compression bra for 1–2 weeks. No pressure dressing over the SLNB site.
• Follow-up:
  • Wound check at 1–2 weeks.
  • Path review meeting: margins, node status, receptor / HER2 status, Oncotype / MammaPrint if applicable.
  • Med onc + rad onc referrals as indicated.
  • Whole-breast radiation typically 4–6 weeks post-op.
• Red flags:
  • Expanding hematoma → immediate return to OR.
  • Seroma requiring aspiration — outpatient.
  • Wound infection at 5–10 days.
• Lymphedema surveillance — every visit for the first 2 years; refer to lymphedema therapy for early signs (heaviness, tightness, subtle increase in arm circumference). SOZO (bioimpedance spectroscopy) baseline preop and every 3–6 months for 3 years, then annually, is standard at Baylor and increasingly the community standard — a rising L-Dex score triggers early compression before clinically overt lymphedema.

Clinical Pearls

• Every SLNB attempt should hit ~95% detection rate with dual tracer. If you’re not finding the node, revisit tracer technique before making the axilla bigger.
• Orient every specimen. Path can’t call margins accurately without orientation.
• Place clips at the cavity walls every time — rad onc needs them for the boost.
• Cavity shave margins are cheap oncologic insurance — reduces re-excision by ~50% in the SHAVE trial.
• Don’t inject methylene blue into the dermis — you’ll cause skin necrosis and a permanent “blue tattoo.”
• For any localization marker system, know the artifact profile for the patient’s downstream imaging plan.
• Take the pectoral fascia with any tumor near it.
• Verify Magseed / Magtrace probe compatibility with your OR’s instrument set before the case — some standard steel retractors will degrade the signal.
• Intercostobrachial nerve — you can sacrifice it if it’s in the way, but tell the patient preop that medial-arm numbness is common.

Quick Reference Table — Localization Systems

Quick-Reference Cards

Related Case Preps

• Total Mastectomy ± SLNB — if BCT is contraindicated or the patient chooses mastectomy.
• Axillary Lymph Node Dissection — if > 2 positive SLNs, ineligible for Z0011, or clinically positive axilla.
• Modified Radical Mastectomy — total mastectomy + level I–II ALND en bloc.

Related Topic Reviews

• Breast — staging, screening, systemic therapy, ABSITE-level pearls.

References

1. Giuliano AE, Ballman KV, McCall L, et al. Effect of axillary dissection vs no axillary dissection on 10-year overall survival among women with invasive breast cancer and sentinel node metastasis: the ACOSOG Z0011 randomized clinical trial. JAMA. 2017; 318(10): 918–926. (Z0011 long-term).
2. Moran MS, Schnitt SJ, Giuliano AE, et al. SSO-ASTRO consensus guideline on margins for breast-conserving surgery. Ann Surg Oncol. 2014; 21(3): 704–716. (“no ink on tumor”).
3. Morrow M, Van Zee KJ, Solin LJ, et al. SSO-ASTRO-ASCO consensus guideline on margins for breast-conserving surgery with whole-breast irradiation in DCIS. JCO. 2016; 34(33): 4040–4046. (2 mm for DCIS).
4. Chagpar AB, Killelea BK, Tsangaris TN, et al. A randomized, controlled trial of cavity shave margins in breast cancer (SHAVE). NEJM. 2015; 373(6): 503–510.
5. Boughey JC, Suman VJ, Mittendorf EA, et al. Sentinel lymph node surgery after neoadjuvant chemotherapy in patients with node-positive breast cancer: ACOSOG Z1071 (Alliance). JAMA. 2013; 310(14): 1455–1461.
6. Giuliano AE, McCall L, Beitsch P, et al. Locoregional recurrence after sentinel lymph node dissection with or without axillary dissection in patients with sentinel lymph node metastases (Z0011). Ann Surg. 2010; 252(3): 426–432.