There is controversy surrounding the optimal radiotherapy dose-fractionation for retreatment of painful bone metastases. Two commonly used regimens are 8 Gy in a single-fraction or 20 Gy in five or eight fractions. Randomized evidence, including the NCIC SC.20 randomized clinical trial, has failed to standardize clinical practice. Practitioners who use single-fraction regimens cite patient convenience, fewer acute adverse effects, and better cost-effectiveness. Practitioners who prefer multiple fractions raise questions about the interpretation of data that justifies single-fraction treatment, and the possibility that single-fraction treatment may provide inferior pain relief. Given this clinical controversy, should single-fraction irradiation be standard in retreatment of uncomplicated bone metastases? In this article, two teams debate both sides of the argument with commentary to summarize the relevant issues. The conclusion from the debate is that the “standard” treatment should be individualized to the patient with shared-decision making between the oncologist, patient and family members. In a cancer patient with poor performance status and short life expectancy, single-fraction repeat radiotherapy may be preferred; in a patient with a prolonged disease course, perhaps multiple fraction retreatments would be preferred. The choice between different fractionation schemes depends on an assessment of individual patient factors, tumour factors and unique patient circumstances.
