Dave Mustaine's oncologist co-wrote MEGADETH's ‘Dogs Of Chernobyl’.

Dr. Anthony J. Cmelak of Nashville’s Vanderbilt University Medical Centre has revealed that after he treated the guitarist for throat cancer in 2019, he was given a songwriting credit on the ‘The Sick, The Dying… And The Dead!’ song after he helped with the medical terminology for radiation.

Speaking with The Tennessean, Cmelak said: “I think [Mustaine] wanted descriptive terminology on how your bodily functions would change after exposure to massive doses of radiation.

“He also wanted a flair of someone being left behind … I geared toward that and it came around very quickly.”

The lyrics include: "Nausea overwhelms my brain, distance is the goal.

"Stomach spasms, leaking gut, I have lost all control.

"Saliva gurgling, I'm retching, till I overwhelm the bowl."

The doctor also shared how Mustaine “seemed" to take his cancer diagnosis in his "stride".

The 61-year-old thrash metaller underwent 51 radiation treatments and nine chemotherapy sessions before being declared cancer-free in February this year.

He was still working on the band's latest album through the ordeal because it distracted him from his treatment.

However, the hardest part of all was dealing with "chemo brain".

He recently shared: "I think it did (distract him), to a degree.

"The toughest part wasn't the process of going through all the radiation and chemotherapy, a lot of the cancer medication they gave me f***** with my memory really bad.

"They call it chemo brain, so I've been having a hard time staying in the moment, but it's getting better."

And when asked whether he's thinking of retiring, Mustaine insisted for as long as he can still pick up and play his instrument, he'll keep shredding.

He replied: "When I got sick I had been talking a lot about playing out a little less.

"Now, if anything, I want to tour more and just carry on until the end when I actually can't do it anymore.

"I'm not talking about the time when I don't want to do it anymore.

"I mean when it's not possible for me to do.

"When I can't do it, that's when I'm not gonna want to do it."