Now, Nguyen et al. report the results of the first prospective randomized clinical trial. The trial was conducted at MD Anderson from 2014 to 2018 among 160 people with painful bone metastases from any of a variety of cancer types.
- Half received 12 Gy in a single fraction for ≥ 4 cm bone lesions, or 16 Gy in a single fraction for < 4 cm bone lesions (Single Fraction Cohort - SF)
- Half received 30 Gy in 10 fractions (Multi-Fraction Cohort - MF)
- Treated bone metastases were predominantly non-spinal
- Up to three bone metastases were treated at a time
At all follow-up times (2 weeks, 3 months, 6 months and 9 months):
- Pain palliation (complete+partial) was significantly better among the SF
- At 9 months, pain palliation was 77% for the SF vs 46% for the MF
- In the Single Fraction Cohort, those who got the 16 Gy dose had 3 times better pain palliation vs those who got the 12 Gy dose.
- Local control at 2 years was 100% for SF vs 76% for MF
- Median survival was not significantly different
- No significant differences in toxicity (nausea, vomiting, fatigue, dermatitis, and fracture)
- No significant differences in quality of life
This Phase II study was too small to be definitive, especially for cancer-type subgroups. However, the patient should challenge an radiation oncologist who plans to give more than a single fraction to explain his recommendation. (It is entirely possible the the location of the bone metastasis calls for a lower dose rate.) Moreover, the single fraction dose of 16 Gy or 18 Gy seems optimal for both pain palliation and local control. The patient should not expect this palliative treatment to increase survival.
note: thanks to Valerae Lewis for allowing me to review the full text