Efficacy of single fraction conventional radiation therapy for painful uncomplicated bone metastases: a systematic review and meta-analysis

BACKGROUND: Single fraction radiotherapy (SFRT) and multiple fraction radiotherapy (MFRT) are effective for painful uncomplicated bone metastases and have been shown to be of similar efficacy. The optimal conventional external beam SFRT dose for maximum pain relief remains uncertain. The aim of this systematic review was to comprehensively review and synthesize overall pain response rates by dose.

METHODS: A literature search was conducted in Ovid MEDLINE(R) (1946 to June 2016 week 3), Embase Classic & Embase (1947 to 2016 week 26) and Cochrane Central Register of Controlled Trials (May 2016) using keywords such as bone metastases, radiotherapy and single fraction (SF).

RESULTS: The 635 results from the search were screened, and ultimately 27 were included for quantitative synthesis. The review indicated that 10 and 6 Gy may produce superior overall response (OR) and complete response (CR) rates compared to 8 Gy, and 6 Gy may result in better partial response (PR) than 8 Gy. However, only a few studies documented doses other than 8 Gy. In trials that directly compared 8 Gy to 4 Gy or 6 Gy, 8 Gy was deemed statistically superior.

CONCLUSIONS: 8 Gy SFRT was the most commonly administered dose for palliation of bone metastases supporting its efficacy and safety. Future studies should explore the efficacy of 10 Gy while minimizing its side effects.