A teenager who was repeatedly given a potentially fatal overdose of radiation at a leading cancer unit spoke today of her anger and fears for her future. Lisa Norris, 15, was given the overdose 17 times at the Beatson Oncology Centre in Glasgow, where she was treated for a brain tumour.

"Human error" has been blamed for the mistake. The long-term effects are not yet known, but Lisa said doctors had warned that the overdoses could prove fatal.

The teenager, who lives in Girvan, Ayrshire, began radiation therapy on January 5 following four blocks of chemotherapy at Yorkhill hospital in Glasgow.

She was told last Tuesday that the brain tumour had gone. Then consultants visited her home on Monday to tell her about the error. An investigation has been launched into how the mistake was made.

Lisa told STV's Scotland Today: "I'm very sore and I've got burns on the back of my neck and down my ears. I'm starting to blister and at night I can't sleep because I can't lie on my back.

"We don't know what's in the future because I could be brain-damaged, I could be paralysed. Later in the future, in 10 to 15 years, I could not be here."

She said she was "really angry" with the people responsible. "They shouldn't get away with it. By rights, they should be put out of their job and not allowed back in the NHS ever because it could happen to someone else."

Her father, Kenneth, said: "We were told last week that everything was fine, the tumour had gone, and we were overjoyed by it. And then on Monday her consultants came down and broke the news that they had given her this almighty dose of radiation. It's just knocked us for six. We haven't been able to sleep at night since."

He said he felt "very angry" and distressed. "We want Lisa to get better but we want ... the people involved in this to get sacked from the health board because we don't want this to happen to any other child."

Professor Alan Rodger, the medical director of Beatson Oncology Centre, said: "We will do everything in our power to support both them and their daughter in the challenges ahead."

A spokeswoman for NHS Greater Glasgow said in a statement: "Immediately upon discovering that the patient had been given the radiation overdose, an internal investigation was launched and the Scottish Executive Health Department notified. It has been established that no equipment failure was involved. Initial findings indicate that the overdose was the result of human error and no other patient treatments were compromised."

The statement said that the health department would now conduct a "full inquiry".

Martin Ledwick, the cancer information manager for Cancer Research UK, said that it was difficult to speculate on what might happen to Lisa "as the situation is so unusual".

Mr Ledwick said: "One of the key things that is going to be so difficult for the family is that there is going to be uncertainty about what's going to happen."