Palliative radiation therapy for bone metastases is safe and effective method for managing this painful adverse effect of advanced cancer. In an update to its guidelines for evidence-based clinical palliative radiation therapy, ASTRO reports continued support for its earlier recommendations of radiation dosing schedules of 5, 6, or 10 fractions, but controversy persists for the fourth: a single-fraction treatment.
Painful bone metastases can be safely and effectively treated with any 1 of 4 different radiation dosing schedules, including — controversially — a single-dose treatment, according to updated evidence-based clinical palliative radiation therapy (RT) guideline from the American Society for Radiation Oncology (ASTRO).1
“Available literature continues to support pain relief equivalency between single and multiple fraction regimens for bone metastases,” reported lead study investigator Stephen Lutz, MD, of the department of radiation oncology, Eastern Woods Radiation Oncology in Findlay, Ohio, and co-investigators.1 “High-quality data confirm single fraction radiation therapy (RT) may be delivered to spine lesions with acceptable late toxicity.”
The updated guideline confirms ASTRO’s 2011 recommendations, which include 4 external-beam radiotherapy fractionation schedules for previously untreated metastatic bone tumors:
- 8 Gy in a single fraction
- 20 Gy in 5 fractions
- 24 Gy in 6 fractions
- 30 Gy in 10 fractions
The findings were based on a systematic review of 20 randomized controlled trials, 32 prospective nonrandomized trials, and 4 pooled-data meta-analyses.1 The guidelines address 8 questions in all, with 100% consensus among the 8 panel members; the strength of the recommendation was “strong” for all 8 recommendations, based on a “high” strength of evidence for 5 and a “moderate” strength of evidence for 3 of the 8 questions.1 The fractionation schedules (listed above) represent the first question in the guidelines.
“The panel’s conclusion remains that surgery, radionuclides, bisphosphonates, or kyphoplasty/vertebroplasty do not obviate the need for external beam radiation therapy,” they noted.1
The guideline authors also noted that findings from a single prospective randomized clinical trial confirmed that retreatment of painful spinal or peripheral metastases is safe and effective.1