External Beam Radiation Therapy for Palliation of Symptomatic Bone Metastases: An ASTRO Clinical Practice Guideline

Purpose This guideline provides evidence-based recommendations for palliative external beam radiation therapy (RT) in symptomatic bone metastases. Methods The American Society for Radiation Oncology (ASTRO) convened a task force to address 5 key questions regarding palliative RT in symptomatic bone metastases. Based on a systemic review by the Agency for Health Research and Quality, recommendations using predefined consensus-building methodology were established; evidence quality and recommendation strength were also assessed. Results For palliative RT for symptomatic bone metastases, RT is recommended for managing pain from bone metastases and spine metastases with or without spinal cord or cauda equina compression. Regarding other modalities with RT, for patients with spine metastases causing spinal cord or cauda equina compression, surgery and postoperative RT are conditionally recommended over RT alone. Furthermore, dexamethasone is recommended for spine metastases with spinal cord or cauda equina compression. Patients with non-spine bone metastases requiring surgery are recommended postoperative RT. Symptomatic bone metastases treated with conventional RT are recommended 800 cGy in 1 fraction (800 cGy/1fx), 2000 cGy/5fx, 2400 cGy/6fx, or 3000 cGy/10fx. Spinal cord or cauda equina compression in patients ineligible for surgery and receiving conventional RT are recommended 800 cGy/1fx, 1600 cGy/2fx, 2000 cGy/5fx, or 3000 cGy/10fx. Symptomatic bone metastases in selected patients with good performance status without surgery or neurological symptoms/signs are conditionally recommended SBRT over conventional palliative RT. Spine bone metastases re-irradiated with conventional RT are recommended 800 cGy/1fx, 2000 cGy/5fx, 2400 cGy/6fx, or 2000 cGy/8fx; non-spine bone metastases re-irradiated with conventional RT are recommended 800 cGy/1fx, 2000 cGy/5fx, or 2400 cGy/6fx. Determination of an optimal RT approach/regimen requires whole person assessment, including prognosis, previous RT dose if applicable, risks to normal tissues, quality of life, cost implications, and patient goals and values. Relatedly, for patient-centered optimization of treatment-related toxicities and quality of life, shared decision-making is recommended. Conclusions Based on published data, the ASTRO task force's recommendations inform best clinical practices on palliative RT for symptomatic bone metastases.