Former U.S. President Jimmy Carter said on Thursday he will start radiation treatment for cancer on his brain later in the day.
Carter, 90, said he will cut back dramatically on his schedule to receive treatment every three weeks after doctors detected four spots of melanoma on his brain following liver cancer surgery.
Carter served as president from 1977 to 1981, his one-term in the White House defined by national economic struggles and the embarrassing Iran hostage crisis. He won the Nobel Peace Prize in 2002.
Carter entered a news conference at the nonprofit Carter Center bearing his name in Atlanta walking normally, smiling, and wearing blue jeans.
"I am perfectly at ease with whatever comes," Carter said, noting his deep Christian faith. He said he was pleased that he did not become angry or despaired. "I am ready for anything and looking forward to a new adventure."
The news that cancer had spread to his brain came a week after he revealed his liver surgery found the disease had spread to other parts of his body.
He announced at that time that he was rearranging his schedule to receive treatment at Emory Healthcare in Atlanta, where he previously underwent elective surgery to remove a small mass in his liver. His prognosis was then considered excellent, the Carter Center said in a statement earlier this month.
Yet with his father and his three siblings having died of pancreatic cancer, the disease has long been a concern for Carter. His mother also had pancreatic cancer, in addition to breast and bone cancer.
The centrist former governor of Georgia is credited with helping to stabilize the Middle East as a result of the 1978 Camp David accords between Israel and Egypt.
After losing re-election to Republican Ronald Reagan, he went on to champion wide-ranging international humanitarian efforts.
He published his latest book last month, titled "A Full Life: Reflections at Ninety."
In a wide-ranging interview last month about his life with Reuters Editor-at-Large Sir Harold Evans, Carter reflected on his childhood in a home without running water or electricity and his concerns about ongoing racial prejudice in the United States.
Carter and his wife, Rosalynn, have three sons and a daughter. They live in rural Plains, Georgia, about 150 miles (240 km) south of Atlanta, where he has remained a Baptist church deacon and a Sunday school teacher, according to the Carter Center.