A Study to Assess How Radium-223 Distributes in the Body of Patients With Prostate Cancer Which Spread to the Bones

In this study researcher want to gain more information on how the study drug (radium-223) is distributed in the bone, particularly in the tumor free bone in participants with prostate cancer. The study plans to enroll 60 patients with the age of at least 18 years and suffering from prostate cancer which has spread to the bones. Researcher will divide the study participants into 2 groups. Patients in Group 1 should have up to 6 bone metastases and patients for group 2 should have more than 6 bone metastases. The study medication will be given as injection into a vein every 4 weeks up to a maximum of 6 times. To study how radium distributes in the body and particularly in the bones, participants will undergo after study medication intake MRI or CT Scans (imaging techniques).