The spread of tumour to the bone (metastasis) is a common characteristic of many malignancies including cancers of the prostate, breast and lung. This may be associated with pain, compression of the spinal cord and the potential for bone fracture. Radiotherapy is used to treat bone metastases, however, the optimum treatment schedule is unclear. This review compares whether a single fraction of radiotherapy is better than multifractions of radiotherapy for alleviating the symptoms associated with tumours that have spread to the bone. Eleven randomised trials were identified in the published literature that compared single versus multifraction radiotherapy for bone metastases. Pooled analysis of these trials suggested that single fraction radiotherapy was as effective as multifraction radiotherapy in controlling bone pain. However, there were more bone fractures in patients treated by single fraction radiotherapy, and they received further treatment sessions more often than those receiving multifraction radiotherapy.
Single fraction radiotherapy was as effective as multifraction radiotherapy in relieving metastatic bone pain. However, the retreatment rate and pathological fracture rates were higher after single fraction radiotherapy. Studies with quality of life and health economic end points are warranted to find out the optimal treatment option.
Recent randomised studies reported that single fraction radiotherapy was as effective as multifraction radiotherapy in relieving pain due to bone metastasis. However, there are concerns about the higher retreatment rates and the efficacy of preventing future complications such as pathological fracture and spinal cord compression by single fraction radiotherapy.
To undertake a systematic review and meta-analysis of single fraction radiotherapy versus multifraction radiotherapy for metastatic bone pain relief and prevention of bone complications.
Trials were identified through MEDLINE, EMBASE, Cancerlit, reference lists of relevant articles and conference proceedings. Relevant data was extracted.
Randomised studies comparing single fraction radiotherapy with multifraction radiotherapy on metastatic bone pain
The analyses were performed using intention-to-treat principle. The results were pooled using meta-analysis to estimate the effect of treatment on pain response, re-treatment rate, pathological fracture rate and spinal cord compression rate.
Eleven trials that involved 3435 patients were identified. Of 3435 patients, 52 patients were randomised more than once for different painful bone metastasis sites. Altogether, 3487 painful sites were randomised. The trials included patients with painful bone metastases of any primary sites, but were mainly prostate, breast and lung. The overall pain response rates for single fraction radiotherapy and multifraction radiotherapy were 60% (1059/1779) and 59% (1038/1769) respectively, giving an odds ratio of 1.03 (95% confidence interval [CI], 0.89 to 1.19) indicating no difference between the two radiotherapy schedules. There was also no difference in complete pain response rates for single fraction radiotherapy (34% [497/1441]) and multifraction radiotherapy (32% [463/1435]) with an odds ratio of 1.11 (95% CI 0.94 to 1.30). Patients treated by single fraction radiotherapy had a higher re-treatment rate with 21.5% (267/1240) requiring re-treatment compared to 7.4% (91/1236) of patients in the multifraction radiotherapy arm (odds ratio 3.44 [95% CI 2.67 to 4.43]). The pathological fracture rate was also higher in single fraction radiotherapy arm patients. Three percent (37/1240) of patients treated by single fraction radiotherapy developed pathological fracture compared to 1.6% (20/1236) for those treated by multifraction radiotherapy (odds ratio 1.82 [95% CI 1.06 to 3.11]). The spinal cord compression rates were similar for both arms (odds ratio 1.41 [95% CI 0.72 to 2.75]). Repeated analyses excluding dropout patients gave similar results.