Strontium-89 and samarium-89 are radioactive therapeutic agents used to relieve pain resulting from bone metastases. These agents are administered into a vein, usually in the forearm, by a nuclear medicine physician. The procedure takes 15 to 20 minutes. Prior to the injection, you will meet with a physician or registered nurse who will provide you with the necessary information and address any questions or concerns you might have. The physician or registered nurse will also obtain the required blood work, your weight, and make sure that you have had a bone scan within the last three months. Based on your bone scan, x-rays may need to be performed. Samarium-153 and strontium-89 localize preferentially in skeletal metastases. These agents may also produce a temporary suppressive effect on the bone marrow. Therefore, it may be necessary to obtain blood counts every two weeks, for three months following the injection of strontium-89 and for two months after the injection of samarium-153.