Palliative radiotherapy of bone metastases: an evaluation of outcome measures

The objective of this study was to identify and evaluate important patient- based outcomes that are specific to the palliative radiotherapy of bone met astases. We first conducted a literature review to identify and evaluate ou tcomes that are currently in use. To identify outcomes that are important t o patients, in-depth patient interviews were conducted. Finally, issues ide ntified through the interviews were quantified through a prospective survey , in which patients completed a questionnaire prior to commencing radiother apy and again after 6 weeks. In our literature review we found that there w as no standardized definition of either response to radiotherapy or assessm ent of pain relief. Pain measurement in many studies was undertaken using v ery simple measures, which could possibly yield inaccurate results. The vas t majority of studies did not include quality of life as an endpoint. The p atient interviews and survey showed that chronic pain and associated limita tion of movement were the disease symptoms causing the most concern. Having a clear, alert mind and being able in self-care were the aspects of daily living given the highest priority. Sustained pain relief and minimizing the risk of future complications were the main priorities relating to radiothe rapy treatment. The practical aspects of treatment (travelling distance, re maining at home and brevity of treatment) were of least importance. This st udy indicates the complexity of evaluating the outcomes of palliative inter ventions, and confirms the deficiencies of pain relief as the primary end-p oint. The patient's quality of life is affected by many factors other than pain (such as limited mobility, reduced performance, side effects and impai red role functioning); hence a wider range of end-points is required. Great er sensitivity is required than in currently used end-points. Concurrent di seases as well as concurrent therapies can make it difficult to attribute e ffects with precision. Unless such factors are considered in research desig n, the results may prove unreliable.