Measuring the benefit and toxicity of palliative radiotherapy

Historically, the goal of treatment in most cancer studies has been to improve survival, accepting variable levels of toxicity if survival can be improved. However, with palliative treatment, the goal is seldom to prolong survival but rather to alleviate symptoms and maintain quality of life and functional level while minimizing toxicity and patient inconvenience for those whose life expectancy is often short. Outcome measures for studies comparing palliative treatments are therefore often different and less objective than the more easily measured survival endpoint of curative studies. There are usually multiple outcomes of interest, many of them ideally requiring assessment by the patients themselves, repeatedly, over time. This can cause methodologic, statistical, and administrative difficulties which must be recognized and addressed when planning and conducting such studies. The following paper reviews some of these difficulties that challenge us when we attempt to accurately measure and compare the benefit and toxicity of palliative treatment. Despite these difficulties, the need for such studies is great, given their relative rarity in the published literature thus far and the magnitude of the clinical problem of palliative care.