Y-90 radioembolization is a type of targeted internal radiation therapy used to treat liver cancer. During this procedure, radioactive microspheres containing Yttrium-90 are injected directly into the blood vessels that supply the tumor in the liver. The radiation targets and destroys cancer cells while minimizing damage to surrounding healthy tissue. Y-90 radioembolization is often used as a treatment option for patients with liver cancer that is unable to be surgically removed or has spread to the liver from another site in the body. It is typically used in combination with other treatments such as chemotherapy or surgery.