The guideline was needed to update previous recommendations and incorporate new high-quality evidence for the management of symptomatic bone metastases, Sara Alcorn, MD, PhD, of the University of Minnesota, Minneapolis, and colleagues wrote in Practical Radiation Oncology.
The focus was on the efficacy of EBRT in reducing pain, improving skeletal function, and enhancing quality of life, they wrote in the clinical practice guideline.
In developing their recommendations, the ASTRO task force reviewed evidence from 53 randomized controlled trials (RCTs) and 31 nonrandomized studies, and considered clinical experience.
Indications for Palliative Radiation
EBRT is strongly recommended for reducing pain from osseous metastasis and improving ambulatory status, sphincter function, and reducing pain in patients with spinal metastases causing compression of the spinal cord or cauda equina.
For patients with symptomatic bone metastases and an anticipated life expectancy of at least 4 weeks, EBRT is conditionally recommended to improve quality of life.
Implementation of other Treatments Alongside Palliative Radiation
Instead of RT alone, surgery with postoperative RT is conditionally recommended for patients with compression of the spinal cord or cauda equina.
Postoperative RT is strongly recommended for patients who have undergone surgery for non-spine bone metastases or spine metastases without involving spinal cord or cauda equina compression.
For patients with spinal bone metastases compressing the spinal cord or cauda equina, combining RT with dexamethasone is strongly recommended over RT alone.
Techniques, Dose-Fractionation, and Dose-Constraints for Initial Palliative Radiation
For patients with symptomatic bone metastases undergoing conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 2000 cGy in 5 fractions, 2400 cGy in 6 fractions, or 3000 cGy in 10 fractions.
For patients with spinal bone metastases causing compression of the spinal cord or cauda equina who are not candidates for initial surgical decompression and are treated with conventional palliative RT, strongly recommended doses are 800 cGy in 1 fraction, 1600 cGy in 2 fractions, 2000 cGy in 5 fractions, or 3000 cGy in 10 fractions.
When selecting dose-fractionation, consider patient and disease factors such as prognosis and radiosensitivity, the authors wrote.
Highly conformal planning and delivery techniques, such as intensity-modulated radiation therapy, are conditionally recommended for patients with spinal bone metastases compressing the spinal cord or cauda equina who are receiving dose-escalated palliative RT.
The strongly recommended stereotactic body radiotherapy (SBRT) doses for patients with symptomatic bone metastases are 1200 to 1600 cGy in 1 fraction for non-spine metastases and 2400 cGy in 2 fractions for spine metastases. Other established SBRT dose and fractionation regimens with similar biologically effective doses may be considered based on patient tumor characteristics, normal tissue factors, and physician experience.
For patients with symptomatic bone metastases who have an ECOG PS of 0-2, are not undergoing surgical intervention, and have no neurological symptoms, SBRT is conditionally recommended over conventional palliative RT. Other factors to consider include life expectancy, tumor radiosensitivity, and metastatic disease burden, the guideline says.