Radium-223 is a radioactive isotope of radium that emits alpha particles. It has a half-life of about 11.4 days, making it relatively short-lived compared to other isotopes. Radium-223 is primarily used in medical applications, particularly in the treatment of metastatic bone cancer, where it targets bone tissue and delivers localized radiation to tumors. This radioisotope is produced in nuclear reactors and can be administered to patients through injection. Its ability to selectively accumulate in bone metastases helps to alleviate pain and improve quality of life for individuals suffering from advanced cancer, particularly those with prostate cancer that has spread to the bones.