"Let him go or let them operate and take a chance."
That was the dilemma facing the parents of 13-year-old Lee McMillan after being told their son's illness had got so bad an operation performed only once before on a child was their only chance he would live.
But that "terrifying decision" to give the operation the go-ahead saved the Merseyside teenager's life.
Lee, from Litherland in Sefton, had come home from school one Friday in May saying he had a headache. Three days later his mother Tracy Jennings found him having a seizure.
He was rushed into hospital where he was diagnosed with encephalitis, an infection which causes brain swelling.
Less than a week later, the schoolboy boxing champion was in a coma.
"We went home and called back because he'd been unresponsive," his mother Tracy Jennings said.
"It was awful, I couldn't believe it was happening. A boy came home from school on Friday with a headache and then to be faced with him nearly dying, it just didn't seem real."
Even if Lee survived the groundbreaking operation there was no guarantee of a full recovery.
The doctors could not say if Lee would sustain brain damage or if he would be able to walk or talk again.
"To be put in that position and looking at him lying on that bed and deciding what to do with him was the hardest thing I think any parent could ever do," Ms Jennings said.
"But that's what we were faced with. Let him go or let them operate and take a chance."
"Because it's so rare, we had nothing to base it on and say 'well it's happened to this person and look at him now'. "
Dr Rachel Kneen, consultant paediatric neurologist at Alder Hey hospital, said doctors felt the only option was to operate.
"This was the worst case of encephalitis I've ever seen and despite all the right treatment, medicine and care he was just getting worse and we thought he was going to die.
"The right side of Lee's brain was so swollen it was starting to press on the central important parts which control breathing and keep us alive."
Professor Tom Solomon, who researches brain infections at the Institute of Infection and Global Health at the University of Liverpool, talked through the procedure.
"On this occasion the brain was so tightly squished that we got our surgeons to remove some of the skull and take away the infected brain tissue and that created space for the rest of the brain to recover.
Two months later, Lee's parents said he was defying the odds and was walking, talking and even practising jabs and right-hooks in his hospital room.
And after the high-risk complicated procedure, Lee is going home.
"I used to have loads of headaches but I haven't even had one headache in ages," the teenager said.
"I'm well better now."
Lee said he was looking forward to seeing his friends and going back to boxing.
His mother said: "Obviously looking at him now we made the right decision but it's one I wouldn't wish on anybody.
"To be honest, I don't think it's over yet but he's well on his way to a brilliant recovery.
She added: "At the moment he's like a little miracle boy.
"I've always called him my special boy and this just makes him that much more special now because we're so grateful he's still here."