A Sentimag probe, a device that works in a similar way to a metal detector, is being recommended by NICE in draft guidance to help identify whether breast cancer has spread.

The guidance could help to reduce reliance on radioactive isotope tracers in the potential first change to NHS standard care for years.

Sentimag probe works in a similar way to a metal detector

A non-radioactive dark brown liquid called Magtrace is injected into the tissue surrounding the tumour. The particles are then absorbed into the lymphatic system, following the route that cancer cells are most likely to take when they spread from the primary tumour and become trapped in sentinel lymph nodes.

The Sentimag probe then moves over the skin emitting sounds of different pitches, in a similar way to how a metal detector locates metal in the ground.

Once the sentinel lymph node is located (which are often dark brown or black in colour), the surgeon makes a small incision and removes the node for biopsy.

If cancer is found, the surgeon may remove additional lymph nodes either during the same biopsy procedure or during a follow-up procedure.

New method likely to be as effective as standard current practice and may be more efficient

Evidence suggests this method is likely to be as effective as the standard current practice, and it may be more efficient as it reduces the need for patients to travel the country for biopsies to be taken.

This is because the current method requires nuclear medicine safety procedures and facilities because it uses a radioactive isotope tracer and a blue dye dual technique. Magtrace is not radioactive so does not require these precautions.

Jeanette Kusel, acting director for MedTech and digital at NICE, said: “People with breast cancer want to know if their cancer has been isolated or has spread to the rest of their body. The earlier this is established, the better the potential outcomes will be.

“Using the Magtrace technology is another option for surgeons who work in hospitals with limited or no access to radiopharmacy departments. The benefits of using this technology include the potential for more procedures to take place, reducing the reliance on radioactive isotopes shipped into the country and for less travel for people having a biopsy.”


The draft guidance is now open to public consultation via nice.org.uk until Thursday 16th June 2022.