ATLANTA (TIP): Former US President Jimmy Carter announced on Thursday that he will begin radiation treatment on cancer that is on multiple spots on his brain.

“I get my first radiation treatment for the melanoma in my brain this afternoon,” Carter said during a news conference where he talked openly about his cancer and how he would cut back on his work with the Carter Center.

Carter, appearing in a dark blazer, red tie and jeans and surrounded by friends and family, said at first he thought the cancer was confined to his liver and that the operation he had earlier this month had completely removed it, “so I was quite relieved.”

But that same afternoon, an MRI showed it was on his brain.

“I just thought I had a few weeks left, but I was surprisingly at ease. I’ve had a wonderful life,” Carter, 90, said.

Carter said on Thursday in his first public remarks since his diagnosis that the cancer was first discovered as a tumor on his liver. On Aug 3, he says, he underwent surgery to remove the tumor. He says about one-tenth of his liver was removed.

But he says that later, four spots of melanoma were found on his brain. He says he will have his first radiation treatment on Thursday afternoon.

Carter says he is not feeling despair or anger over his health. He says he feels good, with only slight pain.

He says: ” I’m perfectly at ease with whatever comes. I’m ready for anything. I’m looking forward to a new adventure.”