Frailty-the missing constraint in radiotherapy treatment planning for older adults.

Current demographic changes translate into an increased frequency of cancer in older adults. Available data show that about 45-55% of the new cancer patients will need RT treatments, with an expected increase of 20-30% in the future. To provide the best cancer care it is mandatory to assess frailty, offer appropriate curative treatments to patients and personalise them for the frail. Based on published data, the median prevalence of frailty in older population is about 42%. Recently, the free radical theory of frailty has been proposed stating that oxidative damage is more prevalent in frail patients. In parallel, RT is one of the most frequent cancer treatments offered to older adults and is a source of external free radicals. RT dose constraints correlate with toxicity rates, so we open the question whether frailty should be considered when defining these constraints. Thus, for this paper, we will highlight the importance of frailty evaluation for RT treatment decisions and outcomes.