BACKGROUND: The SentiMAG Multicentre Trial evaluated a new magnetic technique for sentinel lymph node biopsy (SLNB) against the standard (radioisotope and blue dye or radioisotope alone). The magnetic technique does not use radiation and provides both a color change (brown dye) and a handheld probe for node localization. The primary end point of this trial was defined as the proportion of sentinel nodes detected with each technique (identification rate).
METHODS: A total of 160 women with breast cancer scheduled for SLNB, who were clinically and radiologically node negative, were recruited from seven centers in the United Kingdom and The Netherlands. SLNB was undertaken after administration of both the magnetic and standard tracers (radioisotope with or without blue dye).
RESULTS: A total of 170 SLNB procedures were undertaken on 161 patients, and 1 patient was excluded, leaving 160 patients for further analysis. The identification rate was 95.0 % (152 of 160) with the standard technique and 94.4 % (151 of 160) with the magnetic technique (0.6 % difference; 95 % upper confidence limit 4.4 %; 6.9 % discordance). Of the 22 % (35 of 160) of patients with lymph node involvement, 16 % (25 of 160) had at least 1 macrometastasis, and 6 % (10 of 160) had at least a micrometastasis. Another 2.5 % (4 of 160) had isolated tumor cells. Of 404 lymph nodes removed, 297 (74 %) were true sentinel nodes. The lymph node retrieval rate was 2.5 nodes per patient overall, 1.9 nodes per patient with the standard technique, and 2.0 nodes per patient with the magnetic technique.
CONCLUSIONS: The magnetic technique is a feasible technique for SLNB, with an identification rate that is not inferior to the standard technique.
The authors thank the patients and their relatives for participating in this trial. They also thank the research nurses and the National Institute of Health Research (NIHR) for helping recruit patients into the trial; the Clinical Research Coordinator (Medische Spectrum Twente, Enschede, The Netherlands) for helping with patient recruitment and data management; members of the Data Monitoring Committee for their valuable advice (Miss Zoe Winters, Dr. Jane Warwick, and Dr. Jurgen Fütterer); Endomagnetics Ltd. (UK) for providing an educational grant to fund this clinical trial. This work was supported by the Experimental Cancer Medicine Centre Initiative which is jointly funded by Cancer Research UK, the NIHR in England and the Departments of Health for Scotland, Wales and Northern Ireland. The research was also supported by the NIHR Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London. The sponsors of this trial are King’s College London, UK and Guy’s & St Thomas’ Hospitals NHS Foundation Trust.
Unrestricted Education Grant from Endomagnetics Ltd., UK. UK National Institute of Health Research (NIHR) adopted trial.