Mustaine, the metal band’s singer and lead guitarist, said on social media that he is “working closely with my doctors and we’ve mapped out a treatment plan which they feel has a 90% success rate”.
“Treatment has already begun,” he added.
Megadeth has cancelled “most shows this year” to allow Mustaine, 57, to concentrate on his health.
But he said that the 2019 Megacruise would go ahead in October and Megadeth “will be a part of it in some form”.
He also vowed that the band “will be back on the road ASAP”.
Mustaine revealed that he and his bandmates David Ellefson, Kiko Loureiro and Dirk Verbeuren, are working on a follow up to their Grammy Award-winning album Dystopia “which I can’t wait for everyone to hear”.
Mustaine founded Megadeth more than 30 years ago and the band pioneered the sound that would become known as thrash metal.