Biden was already taking a hormone medication pill, and the radiation was newly introduced as part of his cancer care, a spokesperson for the 82-year-old told NBC News.
The 46th president is “doing well,” his team told The Post.
Biden’s post-presidential office announced in May that Biden is battling an aggressive form of prostate cancer.
Biden underwent another procedure to remove cancer cells from his skin in early September.
Biden left office as the oldest serving president after battling questions about his health and mental fitness following the presidential debate disaster that ultimately forced him to abandon his plans for reelection.
The one-term president and former VP has kept a low profile while battling the disease.
But he has maintained talks with California Gov. Gavin Newsom – who served as a top campaign surrogate defending Biden even as he struggled last year, The Washington Post reports.
He has also held talks with Rep. Alexandria Ocasio-Cortez (D-NY) and Sen. Bernie Sanders (D-VT), according to the paper.
Biden will be 83 next month.
News of the former president’s radiation treatment comes hours after President Trump traveled to Walter Reed National Military Medical Center for what the White House physician called his “semi-annual” physical.
Trump got a COVID and flu shot in advance of his trip to Israel and Egypt Sunday.
Trump, 79 remains in “exceptional health,” his physician, Navy Capt. Sean Barbabella, said. The appointment was a “scheduled follow-up evaluation” and said it was a “part of his ongoing health maintenance plan,” Barbabella added.
Trump’s cardiac age, which takes in risk factors, was about 14 years younger than his chronological age, he said.
Trump, 79 remains in “exceptional health,” his physician, Navy Capt. Sean Barbabella, said. The appointment was a “scheduled follow-up evaluation” and said it was a “part of his ongoing health maintenance plan,” Barbabella added.
Trump’s physical follows a July appointment after which the White House announced he suffered chronic venous insufficiency, which contributed to mild swelling in his lower legs and ankles.