At the time, there were fears for Sam's long-term future.
At best, the Stainer family were expecting to have to stay in Christchurch Hospital for ongoing treatment through Christmas and the New Year.
But in an unexpected turn for the better, the family learned Sam's tumour was benign and last Friday he was flown back to Dunedin Hospital, where he will be closely monitored and undergo physical rehabilitation.
''We're pretty stoked about it,'' mother Sandra said.
''Even though we're not at home, we're back in Dunedin for Christmas.
''This is the best Christmas present ever. It's fantastic.''
While Sam has had good and bad days since his surgery, Miss Stainer said the doctors were very impressed with the speed of his recovery.
''He's doing great. He has exceeded the surgeons' expectations and we're hoping for a full recovery,'' she said.
Doctors at Dunedin Hospital are considering letting Sam go home for a couple of hours tomorrow, so he can experience a little bit of normality.
Miss Stainer said the past two years had been very difficult.
Sam had suffered severe migraines, dizziness and double vision and vomited a lot, all of which eventually led to the diagnosis of a brain tumour.
On top of that, Sam's 15-month-old brother, Jayden, has had ear infections. When Sam first awoke from surgery he was very confused, one eye would not open and he was feeling very dizzy, Miss Stainer said.
Yesterday, he was sitting up in bed and smiling, no doubt thrilled by the fact he was back in Dunedin for Christmas.