Chow, E., van der Linden, Y.M., Roos, D., Hartsell, W.F., Hoskin, P., Wu, J.S., . . . Wong, R.K. (2014). Single versus multiple fractions of repeat radiation for painful bone metastases: A randomised, controlled, non-inferiority trial. The Lancet Oncology, 15, 164–171.
To assess two different radiation therapy fractionation approaches in patients with painful bone metastases needing repeat radiation therapy
Patients with radiologically confirmed bone metastases that had previously been treated with radiation were randomized to receive 8 Gy in a single fraction or 20 Gy in multiple fractions. Those getting 20 Gy received treatment in five fractions unless the target field was the spine or whole pelvis. Bone-modifying agents and systemic therapy were allowed at the discretion of the physician. Overall response to treatment was the primary endpoint at two months after beginning treatment. Pain assessments were done at days 7 and 14, monthly for 6 months, and at 9 and 12 months after radiation therapy. A difference of 10% with treatment response was established to determine noninferiority.
Unblinded, randomized, controlled noninferiority trial
In the ITT analysis, 28% in the 8 Gy group had response, and 32% of those in the 20 Gy group had overall response with a confidence interval that did not meet the noninferiority margin. In the per-protocol analysis, 45% of patients in the 8 Gy group and 51% in the 20 Gy group had overall response with a 95% confidence interval that met the 10% noninferiority margin. Patients in the 20 Gy group had more skin reddening and more frequent and severe anorexia, vomiting, and diarrhea (p < .05).
The per-protocol analysis showed that multiple fractionation was associated with slightly better pain response to treatment, but was also associated with more side effects.
Radiation therapy to areas of painful bone metastases is effective in reducing pain. Though a higher total dose was slightly more effective, it was also associated with more side effects. Nurses can use this knowledge to educate patients and to monitor appropriate patients for treatment side effects.