Strontium 89, a radiopharmaceutical, has proved effective in treating pain associated with multiple osteoblastic bony metastasis from prostate or breast cancer. The drug is given intravenously in an outpatient setting. Pain relief may be noted within 1 to 2 weeks and may last for several weeks or months. Radiosensitizers such s idoxuridine incorporate into the DNA and increase the susceptibility of the cancer cell to radiation damage. Hypoxic cell sensitizers (such as metronidazole, misonidazole, SR 2508, and Ro-038799) increase oxygen to the cancer hypoxic cells and promote damage of the DNA, thus preventing cell repair.