A Multicenter Non-Inferiority Randomized Controlled Trial of Sentinel Lymph Node Biopsy in Early Breast Cancer: Conventional Dual Tracer Versus Superparamagnetic Iron Oxide
In brief
Magnetic tracer finds sentinel nodes in 99% of early breast cancers, matching standard
In a multicenter trial of 297 node-negative patients, a single injection of superparamagnetic iron oxide achieved a 99.3% sentinel-node identification rate, essentially identical to the 100% rate with the conventional radioisotope-plus-blue-dye method. The result meets non-inferiority criteria, offering a radiation-free alternative, though long-term outcomes and cost implications remain to be explored.
- Journal
- World journal of surgery (Q1)
- Published
- 31 July 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Chiu Hoi Woon Tiffany, Ray Ka Wai Hung, Kong Wai Chung Angela, Kwok Sin Man, Sheung Robin Lok Man, Violet Yee Kei Tsoi
- PMID
- 42537885
- DOI
- 10.1002/wjs.70498
Why clinicians should know about it
- Picked for Surgery (top studies of the week, 2 August 2026): Non‑inferiority RCT of SPIO vs dual tracer for sentinel node
Abstract
BACKGROUND: The gold standard for detecting sentinel lymph node (SLN) in early breast cancer is combined use of radioisotope and blue dye. A newer agent, superparamagnetic iron oxide (SPIO), was developed to address the challenges faced with the traditional method. This study aims to compare the detection rate of SLN biopsy and show the non-inferiority of SPIO. METHODS: From March 2021 to April 2024, patients with clinically and radiologically node-negative breast cancer were randomized to receive SPIO-only injection or dual tracer for SLN localization. The primary endpoint was the SLN identification rate in both arms. RESULTS: 148 patients were in the SPIO group with 153 SLN procedures performed. SLN localization failed in one patient. The identification rate was 99.3% (95% CI: 95.8-99.9). 149 patients were in the dual tracer group with 156 SLN procedures done. The identification rate was 100% (95% CI: 97.0-99.9). The absolute difference was 0.7% (95% CI: -1.2 to 2.7). CONCLUSION: Our results suggest that SPIO, as a single agent, used in SLN biopsy for early breast cancer is non-inferior to the dual tracer method. It can serve as a good alternative to radioactive isotope and blue dye. TRIAL REGISTRATION: CUHK CREC Ref No. 2019.677-T (https://www.crec.cuhk.edu.hk/).
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.