Secondary bone cancer. Coloured gamma scan of a patient with metastatic prostate cancer. The areas of cancer are bright white. The cancer has metastasised (spread) from the prostate to several bones. The causes of prostate cancer are not known, but it is most prevalent in men over 50 years of age. Treatment is with radiation, chemotherapy, hormone therapy, or surgery to remove the prostate. Gamma scans use a radioactive tracer to highlight tissues in the body. A gamma camera detects the gamma radiation emitted by the tracer.