A scar runs over Shukria Begum's head like a neat pink zip. Her dark hair, sprinkled with grey, has grown back in tufts over the two months that she has spent recovering from brain surgery at London's Royal Free hospital. Begum, 55, has had a brain tumour removed but remarkably, 18 years ago, she had the same operation, in the same hospital, by the same surgeon.

The first time was in November 1989, when Begum was 37 and the mother of two teenage boys. Her surgeon, Robert Bradford, a softly spoken man with small, neat hands, was two days past his 35th birthday and a couple of months into his first job as a consultant neurosurgeon. Was he nervous then? "Very," he says, and laughs. "It was one of my first big operations on my own."

Bradford is one of four consultant neurosurgeons at the Royal Free who operate on 1,200 patients between them a year. What was it like to operate on the same patient 18 years later? "It was quite odd," he says. "Something recurring 18 years afterwards is unusual."

Both times, Begum had a meningioma, a tumour of the dura, one of the outer layers protecting the brain. It is not known what causes it, but it is more common in women and thought to be hormone-related. It is rare, occurring in around one in 38,000 people - although around 15% of brain tumours are meningiomas. The symptoms include headaches, epilepsy, paralysis, memory loss and changes in mood or personality. The majority are not malignant, but they press on the brain. "They are harmful because they increase the pressure inside the head," says Bradford, "which can lead to paralysis or death. It isn't always possible to remove them, especially if they are in the skull base, but Begum's tumour was on the top left side. The second time around was more problematic as the tumour had spread from the left to the right side, crossing the large artery that runs across the brain."

Begum and her husband, Mohammed, moved to Luton from Pakistan in the 1960s. When she was in her 30s she developed epilepsy, and after a CT scan identified the meningioma, Begum was referred to the Royal Free. "I had been having fits," she says. "I was very frightened. My sons were at college and I was worried about how they would cope." After the operation, Begum went home and carried on with her life as normal. She says she experienced no problems until the severe headaches started earlier this year. She went for some scans and "they told me the tumour had come back," she says. "I was so scared, I started crying." Begum was referred to the Royal Free again and found out that Bradford would be her surgeon. Did she recognise him? "Yes, though he looked a bit older," she says. "I felt more comfortable and confident knowing he was going to do it."

What made Bradford's job much harder the first time around was the lack of technology. In 1989, they had to use a small CT scanner. Magnetic resonance imaging (MRI) scanners existed, but weren't yet in most hospitals. "There was only one in London," says Bradford. "It was in the crypt of Marylebone church, and run as a private enterprise. We now have a huge number of MRI scanners in London and around the country."

An angiogram - an injection of dye into an artery to show up the blood vessels in the brain - was also used to help locate the tumour, but this still wasn't as accurate as the modern MRI scans.

"In those days," says Bradford, "We used to spend quite a bit of time planning the flap [the area of scalp that is cut off and folded back to get at the skull]. Now, I can position it in precisely the right place so it doesn't have to be as big as it used to be. Some neurosurgeons don't even shave the patient's hair any more."

Getting inside the centimetre-and-a-half-thick skull used to be a lot harder, too, because they didn't have power tools. First, with a hand drill, Bradford made some small holes. "Then we'd join them up with a Gigli saw. It's like a cheese wire, a very thin saw of steel. It would take about 30 minutes."

These days, it takes around 30 seconds using an electric drill. "The technology makes everything easier. The downside is, you become dependent on it. If all the computers crashed and I had to operate, I could still do it, but the surgeons I'm training now would find it very difficult."

This time Bradford removed a piece of Begum's skull measuring around 10cm by 7cm and then removed the tumour using intricate surgical instruments. The skull was then put back and fixed with titanium plates and screws - sometimes the bone doesn't ever knit back together. There is less than a 1% chance of death with this surgery but up to a 10% risk of paralysis. The first 72 hours after the operation is critical and the patient is carefully monitored for infections or blood clots.

This time, Begum did have a blood clot and had to have another operation to remove that. Did she notice any difference in the way the NHS is run, then and now? "No," she says. "Of course the technology is different, but the people are the same, they're wonderful."

Bradford says he hopes he never has to operate on her again, and Begum laughs.