Hadlow was due to fight Dunedin's Ricky Curline in the undercard of the bout between Joseph Parker and Alexander Flores in Christchurch tomorrow week.
But a scan has ended Hadlow's first crack at the professional level and he admits he was devastated when told of the scan.
"I have had six years of training, of boxing, been a national champion, gone to the Commonwealth Games and was really looking forward to having some fun in the pro ranks. So yeah, I'm gutted that it has happened," he said.
"But I have to respect the process, have to respect Duco Events, and have to respect the results. I haven't got round to making an appointment with a neurologist or going to speak to them."
All he knew was that it was an abnormality in his brain. He felt fine and no different than he had when in the amateur ranks. He had broken his neck 10 years ago when as a gymnast he landed on his head and cracked two vertebrae.
Hadlow said the timing of the withdrawal was unfortunate and it had knocked him for six but "it is what it is" and it was just a case of being smart in the future.
He was going to take the next couple of months off and then seek medical advice. If this was the end of his boxing career, then he would just look to move on to the next chapter of his life.
A personal trainer and youth worker, Hadlow said he was down for a couple of days when he got the results but had bounced back.
When he broke his neck he was 2mm away from severing his spinal cord and becoming a quadriplegic. An experience like that had an impact on his life, he said.
There will be no replacement fighter for Hadlow so Curline no longer has a fight. Duco Events has implemented mandatory brain scans for its fighters.
