Prof Michael Baum, professor emeritus of surgery at UCL, said: ???We don't know the results yet, they won't be available until later this year. But if it works out, many women will be spared six weeks of treatment going back and forth to the radiotherapy centre.??? He added: ???In countries like ours the waiting list for post-operative radiotherapy would vanish at a stroke and we estimate the NHS would be saved ??15 million a year. Women would vote with their feet for this treatment. Furthermore tens of thousands of women in the developing world who live hundreds of miles from a radiotherapy unit, or in countries which cannot afford the multi-million pound investment, will be able to enjoy the advantages of breast conservation, by bringing the radiotherapy unit to the patient.???

Patients are being treated using the Intrabeam, a portable X-ray machine manufactured by the Carl Zeiss Corporation in Germany. This machine gives out X rays of a different quality to the conventional treatment, but which have ???the equivalent effect,??? said Prof Baum.

However, around one in four patients, classed as high risk of their cancer returning, would still have the more conventional from of treatment, Prof Baum added.