Former President Joe Biden on Monday completed a round of radiation therapy as part of his prostate cancer treatment, his spokesperson has confirmed.

His daughter Ashley Biden posted a video on her Instagram story showing Biden ringing the bell at Penn Medicine Radiation Oncology in Philadelphia, a custom practice for cancer patients who complete a major part of their treatment.

“Dad has been so damn brave throughout his treatment. Grateful,” Ashley Biden wrote on a family photo she posted on the social media platform.

Biden’s spokesperson has not disclosed whether the former president will need additional treatment for his cancer.

Biden’s office announced he was diagnosed with an aggressive form of prostate cancer in May, about four months after he exited the White House, after “experiencing increasing urinary symptoms.” The former president was undergoing radiation and hormone therapy as part of his treatment, his office previously said.