Tiny magnetic beads coated in sugar could help doctors to check if a cancer has spread. Once injected into the patient, the beads can be detected using a handheld magnetic wand — similar to a metal detector — and are used to identify the lymph nodes nearest to the cancer.
The lymph nodes form part of the lymphatic system, which drains fluid from tissues all over the body back into the bloodstream. If cancerous cells get into this system, the disease can then spread to other parts of the body.
The key to determining if cancer has spread is identifying the sentinel node — the lymph node that is nearest the tumour.