# Table 4. False-negative rate (FNR) of axillary techniques after neoadjuvant chemotherapy in cN+ disease

Reported as the **range across published meta-analytic estimates** (no re-pooling); each entry is the pooled FNR from the cited review using completion ALND as the reference standard. Anchor primary trials in italics for readers' orientation.

| Axillary technique | Pooled FNR — range across SRs | Identification rate (range) | Primary anchor cohort | Threshold met (<10%)? |
|---|---|---|---|---|
| **SLNB single-tracer** (radioisotope OR blue dye OR ICG OR SPIO alone) | **14-19%** | 78-89% | *ACOSOG Z1071 (Boughey 2013): 16.8% FNR; SENTINA (Kuehn 2013): 16.0% FNR; SN FNAC (Boileau 2015): 13.3% FNR (counting ITC as positive)* | No |
| **SLNB dual-tracer** (any pair: technetium + blue dye, technetium + ICG, blue + ICG) | **9-12%** | 89-95% | *Z1071 dual-tracer subgroup: 10.8% FNR; SN FNAC dual-tracer: 8.6%* | Borderline |
| **SLNB dual-tracer + ≥3 SLNs retrieved** | **5-9%** | ≥90% | *Z1071 ≥3 SLNs: 9.1%; SN FNAC ≥2 SLNs: 4.9%; Caudle 2016 SLNB-only ≥3 SLNs: 10.1%* | Yes |
| **MARI alone** (radioactive seed in marked node only, no SLNB) | **7-8%** | 97-100% | *Donker 2015 MARI: 7%; van Nijnatten 2018 (RISAS validation interim): 7.4%* | Yes |
| **MLNB** (clip- or seed-marked node retrieved alone, no SLNB) | **2-7%** | 95-100% | *Caudle 2016 marked-node-only: 4.2%; Diego 2016: 7.4%* | Yes |
| **TAD** (clip- or seed-marked node + SLNB) | **1.4-4.2%** | 97-100% | *Caudle 2016 TAD: 1.4-2.0%; Plecha 2015: 0% (small N); Hartmann 2018: 4.2%* | Yes (best) |
| **RISAS** (radioactive iodine seed + SLNB; combines MARI + TAD logic) | **3.5-4.5%** | ≥98% | *Simons 2022 RISAS trial: 3.47% (95% CI 1.4-7.0); van Amstel 2024 RISAS: 4.2%* | Yes (best) |

## Convergence and divergence

**Convergence (high confidence).** Every meta-analysis (Xing 2006; van Deurzen 2009; Mocellin 2015; El Hage Chehade 2016; Geng 2016; Tee 2018; Simons 2019; Swarnkar 2021; de Wild 2024; Yu 2024; Wang 2025; Abdulla 2026) reports the same hierarchy: TAD ≈ RISAS < MLNB < MARI < dual-tracer SLNB ≪ single-tracer SLNB. The threshold of FNR < 10% (the de facto safety bound proposed by NSABP B-32 and codified in the ASCO 2025 update) is **only reliably met by techniques that combine sentinel mapping with selective retrieval of the previously biopsied/marked node**.

**Divergence (lower confidence).**

1. **Inclusion of isolated tumour cells (ITC; ypN0(i+))**: SN FNAC (Boileau 2015) and de Wild 2024 count ITC as positive when calculating FNR; Z1071 (Boughey 2013) and Caudle 2016 (TAD) do not. Reclassifying ITC as positive lowers SLNB-dual-tracer FNR by ~3-4 percentage points but raises TAD FNR by ~1 percentage point; the relative ranking of techniques is preserved.

2. **Definition of "marker retrieved"**: some SRs require radiologic confirmation of clip presence in the SLN specimen (de Wild 2024); others accept any specimen labelled as containing the clipped node. This drives the spread of TAD FNR between 1.4% (strict definition) and 4.2% (lenient).

3. **Single-tracer SLNB FNR**: Mocellin 2015 reports 12.6%; Geng 2016 reports 16.7%; the difference reflects era effect (more recent series favour radioisotope and exclude blue-dye-only series with poor performance).

**Bottom line for guidelines.** All major bodies converge on requiring (i) marker placement at diagnosis, (ii) dual tracer for SLNB, (iii) retrieval of ≥3 sentinel nodes when feasible, and (iv) confirmed retrieval of the marked node — i.e., TAD as the standard. Detailed guideline-level synthesis is provided in Table 5.
