A teenager who got nine top-grade GCSEs while receiving radiotherapy for two brain tumours has been named as one of the best students in Britain.

George Hunter said he felt sick as he sat exams in the morning and then went on to exhausting hospital treatment each afternoon.

But the 17-year-old emerged with a set of results of which any healthy teenager would be proud, and now, having gained two A grades in AS-levels, he is hoping to read medicine at university.

George, a sixth-former at Portsmouth grammar school, is one of 21 students who will be honoured next month in the Oxford, Cambridge and RSA (OCR) exam board’s annual awards ceremony.

He told The TES that his surgeon had advised him not to take his GCSEs last year, after two tumours were diagnosed just weeks before he was due to enter the exam hall.

George had been ill for several months, suffering from double vision and having to drink up to 12 litres of water a day becauseone tumour prevented him retaining fluids. But he said: “I wanted to prove to myself that I could do the exams.”

However, the radiotherapy was carried out every day for five weeks, which meant George was unable to do as much revision as he would have liked.

He said: “Sitting in the exam hall, trying to concentrate on not being sick, rather than thinking about the questions, was a challenge”.

He went on to achieve one A grade, six Bs and two Cs.

And the treatment appears to have been a success: it has stopped the tumours, though George has to take a hormone substitute to counter the effects of the radiotherapy and he will continue to have regular hospital checks.

This summer, after gradually returning to a more normal life, George achieved As in physics and chemistry AS.

He is predicted to achieve As in his physics, chemistry and biology A-levels next year. Inspired by his experiences, he hopes to go on to Southampton university to read medicine.

He said: “Things have turned out for the best in every way. I’d like to thank my school, which has been fantastic throughout.”

George is the second pupil from Portsmouth grammar to win an OCR award in two years.

The awards, which embrace GCSE, A-level and vocational courses taken by students in schools, colleges and businesses, will be presented by TV newsreader Fiona Bruce on November 27.

Next week, the country’s biggest exam board, the Assessment and Qualifications Alliance, holds its awards ceremony.