Proxy assessment of patients before and after radiotherapy for brain metastases

Abstract

Proxies of patients with poor performance status could give useful information about the patients' quality of life (QoL). We applied a newly developed questionnaire in a prospective QoL study of patients undergoing radiotherapy for brain metastases in order to make the first move to validate this instrument, and we compared the results with scores obtained using validated patient-completed instruments. From January 2007 to June 2010, 166 patients with previously untreated brain metastases were recruited at 14 centers in Germany and Austria. The EORTC-QLQ-C15-PAL and the brain module BN20 were used to assess QoL in patients at the start of treatment and 3months later. At the same time points, 141 of their proxies estimated the QoL with the new DEGRO brain module (DBM), a ten-item questionnaire rating the general condition as well as functions and impairment by symptoms in areas relevant to patients with brain metastases. At 3months, 85 of 141 patients (60%) with initial response by a proxy were alive. Sixty-seven of these patients (79% of 3-month survivors) and 65 proxies completed the second set of questionnaires. After 3months, QoL significantly deteriorated in all items of proxy-assessed QoL except headache. Correlations between self-assessed and proxy-assessed QoL were high in single items such as nausea, headache, and fatigue. The high correlation between self-assessment and proxy ratings as well as a similar change over time for both approaches suggest that in patients with brain metastases, proxy assessment using the DBM questionnaire can be an alternative approach to obtaining QoL data when patients are unable to complete questionnaires themselves. Our self-constructed and first applied DBM is the only highly specific instrument for patients with brain metastases, but further tests are needed for its final validation.