On Monday, former President Joe Biden concluded an extended radiation therapy regimen for Stage 4 prostate cancer, which has metastasized to his bones.

Biden, who is 82 years old, celebrated this significant milestone at Penn Medicine Radiation Oncology in Philadelphia. He participated in the customary “ringing of the bell,” a poignant tradition symbolizing the end of a cancer patient’s treatment journey.

“Rung the Bell!” announced Ashley Biden, the former president’s daughter, in an Instagram post. She shared a video capturing her father joyfully ringing the silver bell, surrounded by the applause of hospital staff.

Ashley expressed her gratitude, saying, “Thank you to the incredible doctors, nurses, and staff at Penn Medicine. We are immensely thankful.”

A representative for Biden confirmed to CBS News that he had successfully completed several weeks of radiation therapy at the Philadelphia facility, following an announcement from his office on October 11 regarding the treatment.

It’s unclear if Biden, who turns 83 next month, will undergo any other procedures or forms of treatment for his cancer diagnosis. 

In May, Biden was diagnosed an aggressive form of prostate cancer that had metastasized to the bone. 

The disease was characterized by his doctors as high-grade, with a Gleason score of nine out 10, though hormone-sensitive — allowing for management through medication and radiation. 

Concerns over Biden’s health and age mounted in the final year of his presidency, and the cancer diagnosis prompted renewed concern over whether the commander in chief was suffering from a medical issue while in office. 

Biden, looking noticeably frail, was seen in public Saturday for the first time since his office announced the radiation therapy. 

The former president had been attending evening Mass at St. Joseph on the Brandywine, a Roman Catholic church in Greenville, Del., he has frequented for decades.

“Dad has been so damn brave throughout his treatment,” Ashley wrote in a separate Instagram post Monday, including a photo of herself alongside Joe, former first lady Jill Biden and two of the ex-president’s grandchildren. 

“Grateful,” she added.