Treatment of painful bone metastases.

Bone metastases are the most common cause of cancer-related pain. Radiotherapy is a safe and effective therapy and is well established for such a situation. A fractionation regimen with a short overall treatment time (< or =1 week) would be preferred if it was as effective as longer courses (2-4 weeks). Randomized clinical trials and meta-analyses have demonstrated that single-fraction radiotherapy with 1 x 8 Gy is as effective for pain relief as multi-fraction regimens such as 5 x 4 Gy in 1 week or 10 x 3 Gy in 2 weeks. Re-irradiation for recurrent pain in the irradiated region is required more often after single-fraction radiotherapy than multi-fraction radiotherapy; however, re-irradiation following single-fraction radiotherapy is safe and effective. Thus, 1 x 8 Gy is considered the standard regimen for uncomplicated painful bone metastases without pathological fractures or spinal cord compression. Multi-fraction radiotherapy results in significantly better remineralization of the osteolytic bone than single-fraction radiotherapy. Remineralization is important for preventing or treating pathological fractures. Multi-fraction long-course radiotherapy results in fewer recurrences of spinal-cord compression within the irradiated spinal region. Thus, long-course multi-fraction radiotherapy should be reserved for patients with a relatively favorable survival prognosis.