Just five years ago, Carrie Bickmore decided to start a charity called Beanies for Brain Cancer after her husband Greg Lange was taken by brain cancer in 2010.

She captured the hearts of the nation during the emotional Tuesday night episode of The Project, which was dedicated to brain cancer awareness.

By the end of the special, she shared that the total amount of money raised through her charity was a whopping $3.5 million.

The special featured a range of virtual guests racing to support the cause, including Professor Andrew Kaye who retired from the Royal Melbourne Hospital last year.

Professor Kay treated Carrie's late husband for over 10 years, so the reunion between the pair was special.

“Ten years ago, one of the brains operated on by the Professor was my late husband, Greg. But back then, we used to call him Prof,” she said, reading aloud letters her husband had written about the retired surgeon.

“I found some old letters that Greg had written about when he first met you,” Carrie said, going on to read an excerpt.

“We enjoyed some verbal sparring over how much of a dud club (the Hawks) were … The Prof said, all right, you’ve got a brain tumour and we need to get it out or you’ll die. I sat stunned for a minute, the transition from Hawthorn to an operation to avoid death seemed a little quick.

“But that was the Prof. Blunt and to the point.

“I don’t know if it was the plastic brain on the table, or the banter on AFL but I knew right then and there this was the guy for me.”

Carrie took a moment to compose herself as her voice trembled, but asked the Prof if he remembered meeting her late husband.

“I remember him vividly. I remember his extraordinary courage. I never cease to be amazed by the courage of the people that I treat. People say, doctors have to have courage, they have got to be bold. It is not the doctors with the courage, it’s the patients,” he responded as Carrie’s eyes welled with tears.

“Prof, I’m not sure I had the chance to say to you, to your face, thank you for everything you did for Greg, for me and for my family,” Carrie told the doctor.

“We’re sad you’ve retired but thank you for the gift you’ve given so many people over the years and you are an incredibly humble man and would hate the praise but deserve it. We’ll be forever grateful and so glad you were the one to walk with us side-by-side on that journey, thank you.”

“That’s very kind. Carrie, I really deeply appreciate your words. You need to understand that, I’m not a person who shows emotion easily,” he replied.

Carrie, earlier in the special, explained that survival rates haven't changed for brain cancer in 30 years.

“That is not good enough and it won’t change until more research is done and that won’t happen until more money is raised,” she added, going on to thank everybody who urged her campaign to go on amid the pandemic.

“The world is crazy and I want to thank to everybody who said please do the campaign. They are touched. Brain cancer is not stopping because of what we’re going through,” the mum-of-three said.

Carrie initially started the charity after watching her husband go through a 10-year battle with the disease and said that she doesn't want that pain to be experienced by anyone else.