Development of a score predicting survival after palliative reirradiation

Purpose. To develop a prognostic model for predicting survival after palliative reirradiation (PR). Methods and Materials. We analyzed all 87 PR courses administered at a dedicated palliative radiotherapy facility between 20.06.2007 (opening) and 31.12.2009. Uni- and multivariate survival analyses were performed, the previously published survival prediction score (SPS) was evaluated, and a PR-specific prognostic score was calculated. Results. In multivariate analysis, four parameters significantly influenced survival: performance status, use of steroids, presence of liver metastases, and pleural effusion. Based on these parameters, a 4-tiered score was developed. Median survival was 24.5 months for the favorable group, 9.7 and 2.8 months for the two intermediate groups, and 1.1 months for the unfavorable group (P = 0.019 for comparison between the two favorable groups and P ≤ 0.002 for all other pair-wise comparisons). All patients in the unfavorable group died within 2 months. Conclusion. The performance of PR-specific score was promising and might facilitate identification of patients who survive long enough to benefit from PR. It should be validated in independent patient groups, ideally from several institutions and countries.