A science firm in Oxfordshire is helping with a new technique that can assess whether breast cancer has spread without the need for major exploratory surgery.

Harwell-based AEA Technology is supplying sophisticated equipment that helps pinpoint cancerous cells remaining after surgery and gives doctors important information before they decide if further surgery is needed.

The University College of Medicine in Cardiff is co-ordinating the UK trial of this technique, which involves injecting a very low-level radioactive isotope into the tumour site.

The isotope drains out through the lymph system in the same way as cancerous cells collecting in natural traps called sentinel nodes.

About 4,000 female volunteers who are suffering from breast cancer will take part in the trial.

Using an isotope detector called C-Trak, supplied by AEA Technology, surgeons will pinpoint the exact position of the sentinel nodes and remove them. Research suggests that if there are no cancerous cells in the sentinel node the cancer has not spread and there is no need for further traumatic treatment.

C-Trak was developed in the USA by Carewise Medical Products, but in the rest of the world is being marketed by AEA Technology.