Maine’s U.S. Sen. Angus King said he completed his final radiation treatment for “a residual recurrence” of prostate cancer on Tuesday and used the occasion to advocate for improving access to health care.

King posted a picture on Facebook and Instagram of himself with the medical team at George Washington University Hospital in Washington, D.C., where he has been undergoing “completely painless” radiation treatments for the past two months. King thanked the team – as well as his family, friends and staff – and noted that he liked hearing the doctor use the word “eliminate” when discussing the treatment process.

The 74-year-old senator and former Maine governor announced in January that he would undergo additional radiation treatment for prostate cancer first diagnosed in 2015. Although King had surgery to remove the cancer after the initial diagnosis, regular check-ups since then revealed elevated levels of antigens in the prostate area.

“I’ve dodged cancer three times now, and the secret each time has been health insurance which provided for regular check-ups, and early detection in the course of several of those check-ups,” said King, who was also diagnosed with an aggressive form of skin cancer while in his 30s. “This is why for the life of me (literally, in this case), I can’t understand anyone wanting to limit, reduce, or restrict people’s access to health insurance.”

As a member of Congress, King receives health insurance through the Affordable Care Act. He was able to continue carrying out his duties as senator while receiving early-morning radiation treatments in Washington.