Doctors look for and remove the sentinel lymph node in order to assess the stage of breast cancer. This is called a sentinel lymph node biopsy (SLNB). To find the sentinel lymph node, doctors usually inject a blue dye and radioactive tracer into the breast and use a handheld gamma probe (second generation) to locate the nodes whilst the patient is under a general anaesthetic.

The researchers would like to look at a new magnetic tracer (Sienna+) and a magnetic detector (Sentimag) to find where the sentinel lymph nodes are. The magnetic technique is approved for use, and the researchers consider it may be just as good as the blue dye and radioactive tracer, but without the side effects.

In this study the surgeon will be using Sienna+ and Sentimag alongside standard blue dye and radioactive tracer to detect each patient’s sentinel lymph nodes.



The aim of this study is to evaluate the Sentimag/Sienna+ System (Sentimag®) (second generation probe) in clinical routine practice. On the one hand this allows evaluation of the equivalence of the two techniques, and on the other hand this ensures that patients do not experience any possible disadvantages by participating. The hypothesis behind this evaluation is that Sentimag is as efficient as conventional sentinel node mapping.

The programme will compare the Sentimag® with the conventional sentinel lymph node detection with radioactive tracer (combined with blue dye in those centres using the combined technique) and thereby determine whether the new technique is equivalent to the standard technique for sentinel lymph node biopsy (SLNB).

The primary objective is to identify the proportion of SLNBs (detection rate per patient) with either the standard (radioisotope or blue dye and gamma probe) or the magnetic technique (SPIO and hand-held magnetometer).

Inclusion criteria


Participant enrolled if they:

  • Have primary breast cancer scheduled for SLNB.
  • Are clinically and radiologically node negative.
  • Are aged ≥18 years.
  • Are able and willing to give informed consent.

Participant excluded if they:

  • Are pregnant or lactating.
  • Have metastatic cancer.
  • Had previous axilla surgery, reduction mammoplasty, or have lymphatic function that is impaired in the surgeon’s judgment.
  • Had pre-operative radiation therapy to the affected breast or axilla.
  • Have iron overload disease.
  • Have known hypersensitivity to blue dye and blue dye cannot be omitted.
  • Have an intolerance or hypersensitivity to iron oxide or dextran compounds.
  • Have a pacemaker or other implantable device in the chest wall or shoulder.
  • Are indicated or scheduled for post-operative breast MRI.
  • Have lesions which could pre-operatively only be visualized by breast MRI.
  • Are deprived of liberty or under guardianship, or are unable to follow and understand the study procedures due to mental state or other reasons.

Further information


Please visit the trial website to find out more.