Kathryn Oatey was unsure whether she would have to have her breast removed after being diagnosed with cancer last June.

However, a pioneering new machine, which is the first of its kind in the UK, confirmed on Friday (January 18) that she will not have to undergo the traumatic surgery.

The PET scanner, which has just been unwrapped at the Royal Free Hospital in Hampstead, promises the latest in breast scanning technology, with its ability to detect smaller lumps and track progress at earlier stages of cancer treatment.

The state-of-the-art machine is only available at three other hospitals in the world, but patients who visit the hospital in Pond Street now have the innovative technology on their doorsteps.

Ms Oatey, who was the first woman in the UK to have the scan, said: “I really didn’t want to have a mastectomy. The PET confirmed that the cancer was small enough to have a lumpectomy.

“We were pretty sure that that was the case, but this just confirmed it so that was good news. I was obviously happy.”

She added: “My surgeon had just taken delivery of it and he asked me if I wanted to be the first person in the country to use it.

“I already had chemo and the lump had reduced but this is more accurate and can show something that’s much smaller.

“It’s a great advancement in medical science.”

The Royal Free currently uses MRI scans, mammograms and ultrasound to detect cancer.

Mo Keshtgar, an oncology surgeon at the hospital, said the breast PET scanner was “the latest weapon in its armoury”.

The machine uses new technology to produce a 3D image of the chest and allows doctors to study metabolic activity.

This involves injecting the patient with a small amount of radioactive glucose and watching it light up in spots where cancer cells are presents.

Mr Keshtgar said: “It will be an especially useful tool in younger patients with dense breasts, when it is often harder to detect cancer using a mammogram and we also know that breast density is associated with increased breast cancer risk.”

Because the machine can detect progress at an earlier stage, it is possible to tell whether a patient is responding to treatment or whether alternative therapies should be considered.

The new machine also promises greater comfort for women who are advised to have mammograms as part of a routine check-up in their 40s.

“Its much more comfortable than an ordinary mammogram, which compresses the breast,” said Ms Oatey.

“This is all done in 3D so it doesn’t have to do that.”