The American Society for Radiation Oncology (ASTRO) is issuing an updated clinical guideline that underscores the safety and effectiveness of palliative radiation therapy (RT) for treating painful bone metastases. The guideline recommends optimal RT dosing schedules for pain relief, including options for retreatment.1  

The updated guideline maintains the 4 previously recommended dosing schedules for external RT to treat previously unirradiated tumors: a single 8 Gy fraction of RT; 20 Gy administered in 5 fractions; 24 Gy in 6 fractions; or 30 Gy in 10 fractions. Research indicates that patients experience similar pain relief and toxicity rates with each of the fractionation options. Clinical trials have cited higher retreatment rates for patients who received single-fraction RT. However, the convenience of this option may make it the optimal choice for patients with limited life expectancy.

In addition to primary treatment, the guideline also addresses retreatment of bone metastases. It recommends that reirradiation should be considered if patients experience recurrent or persistent pain more than a month following external-beam radiation therapy (EBRT) to treat peripheral bone metastases or spine lesions.

The guideline considers the role of advanced RT techniques, such as stereotactic body radiation therapy (SBRT), in primary treatment and retreatment of painful bone metastases. While emerging evidence points to the potential of SBRT to treat spinal metastases, research in this area is limited compared with the data supporting EBRT.  Subsequently, the guideline recommends that the use of advanced RT techniques for primary treatment or retreatment of spinal lesions should be considered only in clinical trial or registry settings.

Reference

1. Lutz S, Balboni T, Jones J, et al. Palliative radiation therapy for bone metastases: Update of an ASTRO Evidence-Based Guideline. Pract Radiat Oncol. 2017 Jan – Feb;7(1):4-12. doi: 10.1016/j.prro.2016.08.001 Epub 2016 Aug 5.