Radiation Therapy for Painful Bone Metastases: Fractionation, Recalcification, and Symptom Control

Bone is a common site for metastases, which may cause pain and other skeletal-related events (SRE) in patients with advanced cancer. Since the 1980s, prospective clinical trials have demonstrated the high efficacy of external beam radiotherapy (EBRT) for pain relief from focal, symptomatic lesions. In uncomplicated bone metastases, which include those without pathologic fracture, evidence of cord compression, or prior surgical intervention, improvement or complete pain relief with radiotherapy is as high as 60%, with no difference in efficacy when radiotherapy is delivered in a single or multiple fractions. The ability to treat with a single fraction makes EBRT an attractive therapy even for patients with poor performance status and/or life expectancy. Even in patients with complicated bone metastases (eg cord compression), several randomized trials have demonstrated similar rates of pain relief in addition to improved functional outcomes such as ambulation. In this review, we summarize the role of EBRT for alleviating painful bone metastases and explore its role for other endpoints including functional outcomes, recalcification, and prevention of SREs.