Efficacy of multiple fraction conventional radiation therapy for painful uncomplicated bone metastases: A systematic review

Background: Radiation therapy is effective for painful uncomplicated bone metastases, with multiple fraction radiation therapy (MFRT) administered frequently. The optimal dose for MFRT to yield maximum pain relief remains unclear. The aim of this systematic review was to determine pain response across MFRT doses.

Methods: A literature search was conducted in Ovid MEDLINE(R) <1946 to July Week 3 2016>, Embase Classic & Embase <1947 to 2016Week 30> and Cochrane Central Register of Controlled Trials <June 2016>. Pain response rates and the side effects for MFRT doses were extracted.

Results: From the 3719 articles identified from the search, 17 were included for quantitative synthesis. 22.5Gy/5 had the highest overall response (OR) rate, 30Gy/15 had better complete response (CR) rate and 20Gy/2 had better partial response (PR) rate. Only 4 of the 17 included studies directly compared MFRT doses with each other - one reported marginally-better OR for 24Gy/6 over 20Gy/2; another found 20Gy/10 to be slightly more efficacious than 30Gy/15 and 22.5Gy/5 for OR. Two randomized trials compared 20Gy/5 and 30Gy/10 - one favored 20Gy/5 while the other concluded 30Gy/10 to be the better option. The overall rate of GI toxicities, nausea, and vomiting did not differ greatly between MFRT doses.

Conclusion: No major difference exists between the schedules and toxic events studied in these trials. This is consistent with the wealth of randomized data which show no dose response for pain relief after radiotherapy for metastatic bone pain.